1
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Chen H, Wu W, Du K, Ling A, Kang X. The interplay of growth-regulating factor 5 and BZR1 in coregulating chlorophyll degradation in poplar. PLANT, CELL & ENVIRONMENT 2024. [PMID: 38783695 DOI: 10.1111/pce.14958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 05/09/2024] [Accepted: 05/11/2024] [Indexed: 05/25/2024]
Abstract
Chlorophyll (Chl) is essential for plants to carry out photosynthesis, growth and development processes. Growth-regulating factors (GRFs) play a vital role in regulating Chl degradation in plants. However, the molecular mechanism by which GRF5 regulates Chl degradation in poplar remains unknown. Here we found that overexpression of PpnGRF5-1 increased Chl content in leaves and promoted chloroplast development in poplar. Overexpression of PpnGRF5-1 in poplar delayed Chl degradation induced by external factors, such as hormones, darkness and salt stress. PpnGRF5-1 responded to brassinosteroid (BR) signalling during BR-induced Chl degradation and reduced the expression levels of Chl degradation and senescence-related genes. PpnGRF5-1 inhibited the expression of Chl b reductases PagNYC1 and PagNOL. PpnGRF5-1 could interact with PagBZR1 in the nucleus. PagBZR1 also inhibited the expression of PagNYC1. In addition, we found that the protein-protein interaction between PagBZR1 and PpnGRF5-1 enhanced the inhibitory effect of PpnGRF5-1 on the Chl b reductases PagNYC1 and PagNOL. BZR1 and GRF5-1 were upregulated, and NOL and NYC1 were downregulated in triploid poplars compared to diploids. This study revealed a new mechanism by which PpnGRF5-1 regulates Chl degradation in poplars and lays the foundation for comprehensively analysing the molecular mechanism of Chl metabolism in triploid poplars.
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Affiliation(s)
- Hao Chen
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Wenqi Wu
- Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Kang Du
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Aoyu Ling
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Xiangyang Kang
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- National Engineering Research Center of Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
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2
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Lei P, Jiang Y, Zhao Y, Jiang M, Ji X, Ma L, Jin G, Li J, Zhang S, Kong D, Zhao X, Meng F. Functions of Basic Helix-Loop-Helix (bHLH) Proteins in the Regulation of Plant Responses to Cold, Drought, Salt, and Iron Deficiency: A Comprehensive Review. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:10692-10709. [PMID: 38712500 DOI: 10.1021/acs.jafc.3c09665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Abiotic stresses including cold, drought, salt, and iron deficiency severely impair plant development, crop productivity, and geographic distribution. Several bodies of research have shed light on the pleiotropic functions of BASIC HELIX-LOOP-HELIX (bHLH) proteins in plant responses to these abiotic stresses. In this review, we mention the regulatory roles of bHLH TFs in response to stresses such as cold, drought, salt resistance, and iron deficiency, as well as in enhancing grain yield in plants, especially crops. The bHLH proteins bind to E/G-box motifs in the target promoter and interact with various other factors to form a complex regulatory network. Through this network, they cooperatively activate or repress the transcription of downstream genes, thereby regulating various stress responses. Finally, we present some perspectives for future research focusing on the molecular mechanisms that integrate and coordinate these abiotic stresses. Understanding these molecular mechanisms is crucial for the development of stress-tolerant crops.
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Affiliation(s)
- Pei Lei
- Jilin Provincial Key Laboratory of Tree and Grass Genetics and Breeding, College of Forestry and Grassland Science, Jilin Agricultural University, Changchun 130118, China
| | - Yaxuan Jiang
- College of Life Science, Northeast Forestry University, Hexing Road 26, Harbin 150040, China
| | - Yong Zhao
- College of Life Sciences, Baicheng Normal University, Baicheng 137099, China
| | - Mingquan Jiang
- Jilin Province Product Quality Supervision and Inspection Institute, Changchun 130022, China
| | - Ximei Ji
- Jilin Provincial Key Laboratory of Tree and Grass Genetics and Breeding, College of Forestry and Grassland Science, Jilin Agricultural University, Changchun 130118, China
- College of Life Science, Northeast Forestry University, Hexing Road 26, Harbin 150040, China
| | - Le Ma
- College of Life Science, Northeast Forestry University, Hexing Road 26, Harbin 150040, China
| | - Guangze Jin
- College of Life Science, Northeast Forestry University, Hexing Road 26, Harbin 150040, China
| | - Jianxin Li
- College of Life Science, Northeast Forestry University, Hexing Road 26, Harbin 150040, China
| | - Subin Zhang
- College of Life Science, Northeast Forestry University, Hexing Road 26, Harbin 150040, China
| | - Dexin Kong
- College of Life Science, Northeast Forestry University, Hexing Road 26, Harbin 150040, China
| | - Xiyang Zhao
- Jilin Provincial Key Laboratory of Tree and Grass Genetics and Breeding, College of Forestry and Grassland Science, Jilin Agricultural University, Changchun 130118, China
| | - Fanjuan Meng
- Jilin Provincial Key Laboratory of Tree and Grass Genetics and Breeding, College of Forestry and Grassland Science, Jilin Agricultural University, Changchun 130118, China
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3
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Wang Q, Zhao X, Sun Q, Mou Y, Wang J, Yan C, Yuan C, Li C, Shan S. Genome-wide identification of the LRR-RLK gene family in peanut and functional characterization of AhLRR-RLK265 in salt and drought stresses. Int J Biol Macromol 2024; 254:127829. [PMID: 37926304 DOI: 10.1016/j.ijbiomac.2023.127829] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/22/2023] [Accepted: 10/26/2023] [Indexed: 11/07/2023]
Abstract
Leucine-rich repeat receptor-like kinases (LRR-RLKs) play important roles in plant developmental regulations and various stress responses. Peanut (Arachis hypogaea L.) is a worldwide important oil crop; however, no systematic identification or analysis of the peanut LRR-RLK gene family has been reported. In present study, 495 LRR-RLK genes in peanut were identified and analyzed. The 495 AhLRR-RLK genes were classed into 14 groups and 10 subgroups together with their Arabidopsis homologs according to phylogenetic analyses, and 491 of 495 AhLRR-RLK genes unequally located on 20 chromosomes. Analyses of gene structure and protein motif organization revealed similarity in exon/intron and motif organization among members of the same subgroup, further supporting the phylogenetic results. Gene duplication events were found in peanut LRR-RLK gene family via syntenic analysis, which were important in LRR-RLK gene family expansion in peanut. We found that the expression of AhLRR-RLK genes was detected in different tissues using RNA-seq data, implying that AhLRR-RLK genes may differ in function. In addition, Arabidopsis plants overexpressing stress-induced AhLRR-RLK265 displayed lower seed germination rates and root lengths compared to wild-type under exogenous ABA treatment. Notably, overexpression of AhLRR-RLK265 enhanced tolerance to salt and drought stresses in transgenic Arabidopsis. Moreover, the AhLRR-RLK265-OE lines were found to have higher activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) under salt and drought stress treatments. We believe these results may provide valuable information about the function of peanut LRR-RLK genes for further analysis.
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Affiliation(s)
- Qi Wang
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China.
| | - Xiaobo Zhao
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China
| | - Quanxi Sun
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China
| | - Yifei Mou
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China
| | - Juan Wang
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China
| | - Caixia Yan
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China
| | - Cuiling Yuan
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China
| | - Chunjuan Li
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China
| | - Shihua Shan
- Shandong Peanut Research Institute, Qingdao, Shandong 266100, China.
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4
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Kim SH, Yoon J, Kim H, Lee SJ, Paek NC. Rice Basic Helix-Loop-Helix 079 (OsbHLH079) Delays Leaf Senescence by Attenuating ABA Signaling. RICE (NEW YORK, N.Y.) 2023; 16:60. [PMID: 38093151 PMCID: PMC10719235 DOI: 10.1186/s12284-023-00673-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023]
Abstract
Leaf senescence represents the final phase of leaf development and is characterized by a highly organized degenerative process involving the active translocation of nutrients from senescing leaves to growing tissues or storage organs. To date, a large number of senescence-associated transcription factors (sen-TFs) have been identified that regulate the initiation and progression of leaf senescence. Many of these TFs, including NAC (NAM/ATAF1/2/CUC2), WRKY, and MYB TFs, have been implicated in modulating the expression of downstream senescence-associated genes (SAGs) and chlorophyll degradation genes (CDGs) under the control of phytohormones. However, the involvement of basic helix-loop-helix (bHLH) TFs in leaf senescence has been less investigated. Here, we show that OsbHLH079 delays both natural senescence and dark-induced senescence: Overexpression of OsbHLH079 led to a stay-green phenotype, whereas osbhlh079 knockout mutation displayed accelerated leaf senescence. Similar to other sen-TFs, OsbHLH079 showed a gradual escalation in expression as leaves underwent senescence. During this process, the mRNA levels of SAGs and CDGs remained relatively low in OsbHLH079 overexpressors, but increased sharply in osbhlh079 mutants, suggesting that OsbHLH079 negatively regulates the transcription of SAGs and CDGs under senescence conditions. Additionally, we found that OsbHLH079 delays ABA-induced senescence. Subsequent RT-qPCR and dual-luciferase reporter assays revealed that OsbHLH079 downregulates the expression of ABA signaling genes, such as OsABF2, OsABF4, OsABI5, and OsNAP. Taken together, these results demonstrate that OsbHLH079 functions in delaying leaf yellowing by attenuating the ABA responses.
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Affiliation(s)
- Suk-Hwan Kim
- Department of Agriculture, Forestry and Bioresources, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Jungwon Yoon
- Department of Agriculture, Forestry and Bioresources, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Hanna Kim
- Department of Agriculture, Forestry and Bioresources, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Sang-Ji Lee
- Department of Agriculture, Forestry and Bioresources, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea
| | - Nam-Chon Paek
- Department of Agriculture, Forestry and Bioresources, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Republic of Korea.
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5
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Lei P, Yu F, Liu X. Recent advances in cellular degradation and nuclear control of leaf senescence. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:5472-5486. [PMID: 37453102 DOI: 10.1093/jxb/erad273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Senescence is the final stage of plant growth and development, and is a highly regulated process at the molecular, cellular, and organismal levels. When triggered by age, hormonal, or environmental cues, plants actively adjust their metabolism and gene expression to execute the progression of senescence. Regulation of senescence is vital for the reallocation of nutrients to sink organs, to ensure reproductive success and adaptations to stresses. Identification and characterization of hallmarks of leaf senescence are of great importance for understanding the molecular regulatory mechanisms of plant senescence, and breeding future crops with more desirable senescence traits. Tremendous progress has been made in elucidating the genetic network underpinning the metabolic and cellular changes in leaf senescence. In this review, we focus on three hallmarks of leaf senescence - chlorophyll and chloroplast degradation, loss of proteostasis, and activation of senescence-associated genes (SAGs), and discuss recent findings of the molecular players and the crosstalk of senescence pathways.
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Affiliation(s)
- Pei Lei
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Fei Yu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
- Institute of Future Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xiayan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
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6
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Marková H, Tarkowská D, Čečetka P, Kočová M, Rothová O, Holá D. Contents of endogenous brassinosteroids and the response to drought and/or exogenously applied 24- epibrassinolide in two different maize leaves. FRONTIERS IN PLANT SCIENCE 2023; 14:1139162. [PMID: 37332698 PMCID: PMC10272441 DOI: 10.3389/fpls.2023.1139162] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 05/12/2023] [Indexed: 06/20/2023]
Abstract
Exogenously applied brassinosteroids (BRs) improve plant response to drought. However, many important aspects of this process, such as the potential differences caused by different developmental stages of analyzed organs at the beginning of drought, or by BR application before or during drought, remain still unexplored. The same applies for the response of different endogenous BRs belonging to the C27, C28-and C29- structural groups to drought and/or exogenous BRs. This study examines the physiological response of two different leaves (younger and older) of maize plants exposed to drought and treated with 24-epibrassinolide (epiBL), together with the contents of several C27, C28-and C29-BRs. Two timepoints of epiBL application (prior to and during drought) were utilized to ascertain how this could affect plant drought response and the contents of endogenous BRs. Marked differences in the contents of individual BRs between younger and older maize leaves were found: the younger leaves diverted their BR biosynthesis from C28-BRs to C29-BRs, probably at the very early biosynthetic steps, as the levels of C28-BR precursors were very low in these leaves, whereas C29-BR levels vere extremely high. Drought also apparently negatively affected contents of C28-BRs (particularly in the older leaves) and C29-BRs (particularly in the younger leaves) but not C27-BRs. The response of these two types of leaves to the combination of drought exposure and the application of exogenous epiBL differed in some aspects. The older leaves showed accelerated senescence under such conditions reflected in their reduced chlorophyll content and diminished efficiency of the primary photosynthetic processes. In contrast, the younger leaves of well-watered plants showed at first a reduction of proline levels in response to epiBL treatment, whereas in drought-stressed, epiBL pre-treated plants they were subsequently characterized by elevated amounts of proline. The contents of C29- and C27-BRs in plants treated with exogenous epiBL depended on the length of time between this treatment and the BR analysis regardless of plant water supply; they were more pronounced in plants subjected to the later epiBL treatment. The application of epiBL before or during drought did not result in any differences of plant response to this stressor.
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Affiliation(s)
- Hana Marková
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
| | - Danuše Tarkowská
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany, Czech Academy of Sciences, v.v.i. and Palacký University, Olomouc, Czechia
| | - Petr Čečetka
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
| | - Marie Kočová
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
| | - Olga Rothová
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
| | - Dana Holá
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czechia
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7
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Cao J, Liu H, Tan S, Li Z. Transcription Factors-Regulated Leaf Senescence: Current Knowledge, Challenges and Approaches. Int J Mol Sci 2023; 24:ijms24119245. [PMID: 37298196 DOI: 10.3390/ijms24119245] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/12/2023] [Accepted: 05/14/2023] [Indexed: 06/12/2023] Open
Abstract
Leaf senescence is a complex biological process regulated at multiple levels, including chromatin remodeling, transcription, post-transcription, translation, and post-translational modifications. Transcription factors (TFs) are crucial regulators of leaf senescence, with NAC and WRKY families being the most studied. This review summarizes the progress made in understanding the regulatory roles of these families in leaf senescence in Arabidopsis and various crops such as wheat, maize, sorghum, and rice. Additionally, we review the regulatory functions of other families, such as ERF, bHLH, bZIP, and MYB. Unraveling the mechanisms of leaf senescence regulated by TFs has the potential to improve crop yield and quality through molecular breeding. While significant progress has been made in leaf senescence research in recent years, our understanding of the molecular regulatory mechanisms underlying this process is still incomplete. This review also discusses the challenges and opportunities in leaf senescence research, with suggestions for possible strategies to address them.
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Affiliation(s)
- Jie Cao
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Hairong Liu
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Shuya Tan
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
| | - Zhonghai Li
- State Key Laboratory of Tree Genetics and Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing 100083, China
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8
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Comprehensive Analysis of Betula platyphylla Suk. PIF Gene Family and Their Potential Functions in Growth and Development. Int J Mol Sci 2022; 23:ijms232315326. [PMID: 36499652 PMCID: PMC9738378 DOI: 10.3390/ijms232315326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/26/2022] [Accepted: 11/21/2022] [Indexed: 12/09/2022] Open
Abstract
Phytochrome-interacting factors (PIFs) are transcription factors with the basic helix-loop-helix (bHLH) domain. As integration factors between different signal pathways, members of the PIF protein family regulate many aspects of plant growth and development, such as seed germination, photomorphogenesis, thermomorphogenesis, rhythm regulation, flowering response, stomatal development, and stress responses. Our previous studies have shown that the BpSPL2 gene may regulate plants' adventitious root development through PIF genes. Within the Betula platyphylla genome, we identified eight PIF (BpPIFs) genes. We analysed and named them based on a phylogenetic tree, gene structures, and conserved motifs. Synteny analysis indicated that transposition or segmental duplication events played a minor role in the expansion of BpPIFs. The comparative syntenic analysis combined with phylogenetic analysis provided a deep insight into the phylogenetic relationships of BpPIF genes, suggesting that BpPIF proteins are closer to PtPIF than to AtPIF. The analysis of cis-acting elements in promoter regions of BpPIF genes indicated that various elements were related to light, abiotic stress, and plant hormone responsiveness. In addition, we found that these promoters have the transcription factor of B. platyphylla SPL2 (BpSPL2) binding motif GTAC. Expression analysis demonstrated that BpPIF genes, especially BpPIF4, BpPIF9b, and BpPIF10, might be the potential target genes of BpSPL2 in the process of adventitious root formation. Besides providing a comprehensive understanding of the BpPIF family, we propose a hypothetical gene network regulatory model for adventitious root formation.
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9
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Wang Z, Gao M, Li Y, Zhang J, Su H, Cao M, Liu Z, Zhang X, Zhao B, Guo YD, Zhang N. The transcription factor SlWRKY37 positively regulates jasmonic acid- and dark-induced leaf senescence in tomato. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:6207-6225. [PMID: 35696674 DOI: 10.1093/jxb/erac258] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
Initiation and progression of leaf senescence are triggered by various environmental stressors and phytohormones. Jasmonic acid (JA) and darkness accelerate leaf senescence in plants. However, the mechanisms that integrate these two factors to initiate and regulate leaf senescence have not been identified. Here, we report a transcriptional regulatory module centred on a novel tomato WRKY transcription factor, SlWRKY37, responsible for both JA- and dark-induced leaf senescence. The expression of SlWRKY37, together with SlMYC2, encoding a master transcription factor in JA signalling, was significantly induced by both methyl jasmonate (MeJA) and dark treatments. SlMYC2 binds directly to the promoter of SlWRKY37 to activate its expression. Knock out of SlWRKY37 inhibited JA- and dark-induced leaf senescence. Transcriptome analysis and biochemical experiments revealed SlWRKY53 and SlSGR1 (S. lycopersicum senescence-inducible chloroplast stay-green protein 1) as direct transcriptional targets of SlWRKY37 to control leaf senescence. Moreover, SlWRKY37 interacted with a VQ motif-containing protein SlVQ7, and the interaction improved the stability of SlWRKY37 and the transcriptional activation of downstream target genes. Our results reveal the physiological and molecular functions of SlWRKY37 in leaf senescence, and offer a target gene to retard leaf yellowing by reducing sensitivity to external senescence signals, such as JA and darkness.
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Affiliation(s)
- Zhirong Wang
- College of Horticulture, China Agricultural University, Beijing, China
| | - Ming Gao
- College of Horticulture, China Agricultural University, Beijing, China
| | - Yafei Li
- College of Horticulture, China Agricultural University, Beijing, China
| | - Jialong Zhang
- College of Horticulture, China Agricultural University, Beijing, China
| | - Hui Su
- College of Horticulture, China Agricultural University, Beijing, China
| | - Meng Cao
- College of Horticulture, China Agricultural University, Beijing, China
| | - Ziji Liu
- Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Xichun Zhang
- School of Plant Science and Technology, Beijing Agricultural University, Beijing, China
| | - Bing Zhao
- College of Horticulture, China Agricultural University, Beijing, China
| | - Yang-Dong Guo
- College of Horticulture, China Agricultural University, Beijing, China
- Sanya Institute of China Agricultural University, Sanya, China
| | - Na Zhang
- College of Horticulture, China Agricultural University, Beijing, China
- Sanya Institute of China Agricultural University, Sanya, China
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10
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The RPN12a proteasome subunit is essential for the multiple hormonal homeostasis controlling the progression of leaf senescence. Commun Biol 2022; 5:1043. [PMID: 36180574 PMCID: PMC9525688 DOI: 10.1038/s42003-022-03998-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 09/14/2022] [Indexed: 11/09/2022] Open
Abstract
The 26S proteasome is a conserved multi-subunit machinery in eukaryotes. It selectively degrades ubiquitinated proteins, which in turn provides an efficient molecular mechanism to regulate numerous cellular functions and developmental processes. Here, we studied a new loss-of-function allele of RPN12a, a plant ortholog of the yeast and human structural component of the 19S proteasome RPN12. Combining a set of biochemical and molecular approaches, we confirmed that a rpn12a knock-out had exacerbated 20S and impaired 26S activities. The altered proteasomal activity led to a pleiotropic phenotype affecting both the vegetative growth and reproductive phase of the plant, including a striking repression of leaf senescence associate cell-death. Further investigation demonstrated that RPN12a is involved in the regulation of several conjugates associated with the auxin, cytokinin, ethylene and jasmonic acid homeostasis. Such enhanced aptitude of plant cells for survival in rpn12a contrasts with reports on animals, where 26S proteasome mutants generally show an accelerated cell death phenotype.
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11
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Huang P, Li Z, Guo H. New Advances in the Regulation of Leaf Senescence by Classical and Peptide Hormones. FRONTIERS IN PLANT SCIENCE 2022; 13:923136. [PMID: 35837465 PMCID: PMC9274171 DOI: 10.3389/fpls.2022.923136] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
Leaf senescence is the last stage of leaf development, manifested by leaf yellowing due to the loss of chlorophyll, along with the degradation of macromolecules and facilitates nutrient translocation from the sink to the source tissues, which is essential for the plants' fitness. Leaf senescence is controlled by a sophisticated genetic network that has been revealed through the study of the molecular mechanisms of hundreds of senescence-associated genes (SAGs), which are involved in multiple layers of regulation. Leaf senescence is primarily regulated by plant age, but also influenced by a variety of factors, including phytohormones and environmental stimuli. Phytohormones, as important signaling molecules in plant, contribute to the onset and progression of leaf senescence. Recently, peptide hormones have been reported to be involved in the regulation of leaf senescence, enriching the significance of signaling molecules in controlling leaf senescence. This review summarizes recent advances in the regulation of leaf senescence by classical and peptide hormones, aiming to better understand the coordinated network of different pathways during leaf senescence.
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Affiliation(s)
- Peixin Huang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Research Center for Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Zhonghai Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Research Center for Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Hongwei Guo
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Research Center for Tree Breeding and Ecological Restoration, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Department of Biology, Southern University of Science and Technology, Shenzhen, China
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12
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Pham G, Shin DM, Kim Y, Kim SH. Ran-GTP/-GDP-dependent nuclear accumulation of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 and TGACG-BINDING FACTOR2 controls salicylic acid-induced leaf senescence. PLANT PHYSIOLOGY 2022; 189:1774-1793. [PMID: 35417014 PMCID: PMC9237681 DOI: 10.1093/plphys/kiac164] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 02/08/2022] [Indexed: 05/11/2023]
Abstract
Leaf senescence is the final stage of leaf development and can be triggered by various external factors, such as hormones and light deprivation. In this study, we demonstrate that the overexpression of the GTP-bound form of Arabidopsis (Arabidopsis thaliana) Ran1 (a Ras-related nuclear small G-protein, AtRan1) efficiently promotes age-dependent and dark-triggered leaf senescence, while Ran-GDP has the opposite effect. Transcriptome analysis comparing AtRan1-GDP- and AtRan1-GTP-overexpressing transgenic plants (Ran1T27Nox and Ran1G22Vox, respectively) revealed that differentially expressed genes (DEGs) related to the senescence-promoting hormones salicylic acid (SA), jasmonic acid, abscisic acid, and ethylene (ET) were significantly upregulated in dark-triggered senescing leaves of Ran1G22Vox, indicating that these hormones are actively involved in Ran-GTP/-GDP-dependent, dark-triggered leaf senescence. Bioinformatic analysis of the promoter regions of DEGs identified diverse consensus motifs, including the bZIP motif, a common binding site for TGACG-BINDING FACTOR (TGA) transcription factors. Interestingly, TGA2 and its interactor, NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1), which are two positive transcriptional regulators of SA signaling, differed in their extent of accumulation in the nucleus versus cytoplasm of Ran1T27Nox and Ran1G22Vox plants. Moreover, SA-induced, Ran-GTP-/-GDP-dependent functions of NPR1 included genome-wide global transcriptional reprogramming of genes involved in cell death, aging, and chloroplast organization. Furthermore, the expression of AtRan1-GTP in SA signaling-defective npr1 and SA biosynthesis-deficient SA-induction deficient2 genetic backgrounds abolished the effects of AtRan1-GTP, thus retarding age-promoted leaf senescence. However, ET-induced leaf senescence was not mediated by Ran machinery-dependent nuclear shuttling of ETHYLENE-INSENSITIVE3 and ETHYLENE-INSENSITIVE3-LIKE1 proteins. We conclude that Ran-GTP/-GDP-dependent nuclear accumulation of NPR1 and TGA2 represents another regulatory node for SA-induced leaf senescence.
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Affiliation(s)
| | | | - Yoon Kim
- Division of Biological Science and Technology, Yonsei University, Yonseidae 1 Gil, Wonju-Si 220-710, South Korea
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Yu Y, Qi Y, Xu J, Dai X, Chen J, Dong CH, Xiang F. Arabidopsis WRKY71 regulates ethylene-mediated leaf senescence by directly activating EIN2, ORE1 and ACS2 genes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:1819-1836. [PMID: 34296474 DOI: 10.1111/tpj.15433] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 05/13/2023]
Abstract
Leaf senescence is a pivotal step in the last stage of the plant life cycle and is influenced by various external and endogenous cues. A series of reports have indicated the involvement of the WRKY transcription factors in regulating leaf senescence, but the molecular mechanisms and signaling pathways remain largely unclear. Here we provide evidence demonstrating that WRKY71 acts as a positive regulator of leaf senescence in Arabidopsis. WRKY71-1D, an overexpressor of WRKY71, exhibited early leaf senescence, while wrky71-1, the WRKY71 loss-of-function mutant, displayed delayed leaf senescence. Accordingly, a set of senescence-associated genes (SAGs) were substantially elevated in WRKY71-1D but markedly decreased in wrky71-1. Chromatin immunoprecipitation assays indicated that WRKY71 can bind directly to the promoters of SAG13 and SAG201. Transcriptome analysis suggested that WRKY71 might mediate multiple cues to accelerate leaf senescence, such as abiotic stresses, dark and ethylene. WRKY71 was ethylene inducible, and treatment with the ethylene precursor 1-amino-cyclopropane-1-carboxylic acid enhanced leaf senescence in WRKY71-1D but caused only a marginal delay in leaf senescence in wrky71-1. In vitro and in vivo assays demonstrated that WRKY71 can directly regulate ETHYLENE INSENSITIVE2 (EIN2) and ORESARA1 (ORE1), genes of the ethylene signaling pathway. Consistently, leaf senescence of WRKY71-1D was obviously retarded in the ein2-5 and nac2-1 mutants. Moreover, WRKY71 was also proved to interact with ACS2 in vitro and in vivo. Treatment with AgNO3 and aminoethoxyvinylglycine and acs2-1 could greatly arrest the leaf senescence of WRKY71-1D. In conclusion, our data revealed that WRKY71 mediates ethylene signaling and synthesis to hasten leaf senescence in Arabidopsis.
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Affiliation(s)
- Yanchong Yu
- Shandong Key Laboratory of Plant Biotechnology, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Yanan Qi
- Shandong Key Laboratory of Plant Biotechnology, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Jinpeng Xu
- Shandong Key Laboratory of Plant Biotechnology, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xuehuan Dai
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
| | - Jiacai Chen
- Shandong Key Laboratory of Plant Biotechnology, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Chun-Hai Dong
- Shandong Key Laboratory of Plant Biotechnology, College of Life Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Fengning Xiang
- The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, 266237, China
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Kim Y, Kim SH, Shin DM, Kim SH. ATBS1-INTERACTING FACTOR 2 Negatively Modulates Pollen Production and Seed Formation in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2021; 12:704958. [PMID: 34386030 PMCID: PMC8353282 DOI: 10.3389/fpls.2021.704958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
ATBS1-INTERACTING FACTOR 2 (AIF2) is a non-DNA-binding basic-helix-loop-helix (bHLH) transcription factor. Here, we demonstrate that AIF2 negatively modulates brassinosteroid (BR)-induced, BRASSINAZOLE RESISTANT 1 (BZR1)-mediated pollen and seed formation. AIF2-overexpressing Arabidopsis plants (AIF2ox) showed defective pollen grains and seed production while two AIF2 knockout mutants, aif2-1 and aif2-1/aif4-1, displayed opposite phenotypes. Genes encoding BZR1-regulated positive factors of seed size determination (SHB1, IKU1, MINI3) were suppressed in AIF2ox and genes for negative factors (AP2 and ARF2) were enhanced. Surprisingly, BZR1-regulated pollen genes such as SPL, MS1, and TDF1 were aberrantly up-regulated in AIF2ox plants. This stage-independent abnormal expression may lead to a retarded and defective progression of microsporogenesis, producing abnormal tetrad microspores and pollen grains with less-effective pollen tube germination. Auxin plays important roles in proper development of flower and seeds: genes for auxin biosynthesis such as TCPs and YUCCAs as well as for positive auxin signalling such as ARFs were suppressed in AIF2ox flowers. Moreover, lipid biosynthesis- and sucrose transport-related genes were repressed, resulting in impaired starch accumulation. Contrarily, sucrose and BR repressed ectopic accumulation of AIF2, thereby increasing silique length and the number of seeds. Taken together, we propose that AIF2 is negatively involved in pollen development and seed formation, and that sucrose- and BR-induced repression of AIF2 positively promotes pollen production and seed formation in Arabidopsis.
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Guo Y, Ren G, Zhang K, Li Z, Miao Y, Guo H. Leaf senescence: progression, regulation, and application. MOLECULAR HORTICULTURE 2021; 1:5. [PMID: 37789484 PMCID: PMC10509828 DOI: 10.1186/s43897-021-00006-9] [Citation(s) in RCA: 110] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 03/11/2021] [Indexed: 05/24/2023]
Abstract
Leaf senescence, the last stage of leaf development, is a type of postmitotic senescence and is characterized by the functional transition from nutrient assimilation to nutrient remobilization which is essential for plants' fitness. The initiation and progression of leaf senescence are regulated by a variety of internal and external factors such as age, phytohormones, and environmental stresses. Significant breakthroughs in dissecting the molecular mechanisms underpinning leaf senescence have benefited from the identification of senescence-altered mutants through forward genetic screening and functional assessment of hundreds of senescence-associated genes (SAGs) via reverse genetic research in model plant Arabidopsis thaliana as well as in crop plants. Leaf senescence involves highly complex genetic programs that are tightly tuned by multiple layers of regulation, including chromatin and transcription regulation, post-transcriptional, translational and post-translational regulation. Due to the significant impact of leaf senescence on photosynthesis, nutrient remobilization, stress responses, and productivity, much effort has been made in devising strategies based on known senescence regulatory mechanisms to manipulate the initiation and progression of leaf senescence, aiming for higher yield, better quality, or improved horticultural performance in crop plants. This review aims to provide an overview of leaf senescence and discuss recent advances in multi-dimensional regulation of leaf senescence from genetic and molecular network perspectives. We also put forward the key issues that need to be addressed, including the nature of leaf age, functional stay-green trait, coordination between different regulatory pathways, source-sink relationship and nutrient remobilization, as well as translational researches on leaf senescence.
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Affiliation(s)
- Yongfeng Guo
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101 Shandong China
| | - Guodong Ren
- Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering, School of Life Sciences, Fudan University, Shanghai, 200438 China
| | - Kewei Zhang
- Institute of Plant Genetics and Developmental Biology, College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004 Zhejiang China
| | - Zhonghai Li
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing, 100083 China
| | - Ying Miao
- Fujian Provincial Key Laboratory of Plant Functional Biology, Fujian Agriculture and Forestry University, Fuzhou, 350002 Fujian China
| | - Hongwei Guo
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Department of Biology, Southern University of Science and Technology (SUSTech), Shenzhen, 518055 Guangdong China
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Lee J, Kang MH, Kim JY, Lim PO. The Role of Light and Circadian Clock in Regulation of Leaf Senescence. FRONTIERS IN PLANT SCIENCE 2021; 12:669170. [PMID: 33912212 PMCID: PMC8075161 DOI: 10.3389/fpls.2021.669170] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/23/2021] [Indexed: 05/14/2023]
Abstract
Leaf senescence is an integrated response of the cells to develop age information and various environmental signals. Thus, some of the genes involved in the response to environmental changes are expected to regulate leaf senescence. Light acts not only as the primary source of energy for photosynthesis but also as an essential environmental cue that directly control plant growth and development including leaf senescence. The molecular mechanisms linking light signaling to leaf senescence have recently emerged, exploring the role of Phytochrome-Interacting Factors (PIFs) as a central player leading to diverse senescence responses, senescence-promoting gene regulatory networks (GRNs) involving PIFs, and structural features of transcription modules in GRNs. The circadian clock is an endogenous time-keeping system for the adaptation of organisms to changing environmental signals and coordinates developmental events throughout the life of the plant. Circadian rhythms can be reset by environmental signals, such as light-dark or temperature cycles, to match the environmental cycle. Research advances have led to the discovery of the role of core clock components as senescence regulators and their underlying signaling pathways, as well as the age-dependent shortening of the circadian clock period. These discoveries highlight the close relationship between the circadian system and leaf senescence. Key issues remain to be elucidated, including the effect of light on leaf senescence in relation to the circadian clock, and the identification of key molecules linking aging, light, and the circadian clock, and integration mechanisms of various senescence-affecting signals at the multi-regulation levels in dynamics point of view.
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Zhang YM, Guo P, Xia X, Guo H, Li Z. Multiple Layers of Regulation on Leaf Senescence: New Advances and Perspectives. FRONTIERS IN PLANT SCIENCE 2021; 12:788996. [PMID: 34938309 PMCID: PMC8685244 DOI: 10.3389/fpls.2021.788996] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/03/2021] [Indexed: 05/22/2023]
Abstract
Leaf senescence is the last stage of leaf development and is an orderly biological process accompanied by degradation of macromolecules and nutrient recycling, which contributes to plant fitness. Forward genetic mutant screening and reverse genetic studies of senescence-associated genes (SAGs) have revealed that leaf senescence is a genetically regulated process, and the initiation and progression of leaf senescence are influenced by an array of internal and external factors. Recently, multi-omics techniques have revealed that leaf senescence is subjected to multiple layers of regulation, including chromatin, transcriptional and post-transcriptional, as well as translational and post-translational levels. Although impressive progress has been made in plant senescence research, especially the identification and functional analysis of a large number of SAGs in crop plants, we still have not unraveled the mystery of plant senescence, and there are some urgent scientific questions in this field, such as when plant senescence is initiated and how senescence signals are transmitted. This paper reviews recent advances in the multiple layers of regulation on leaf senescence, especially in post-transcriptional regulation such as alternative splicing.
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Affiliation(s)
- Yue-Mei Zhang
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Pengru Guo
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Xinli Xia
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Hongwei Guo
- Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes, Department of Biology, Southern University of Science and Technology, Shenzhen, China
| | - Zhonghai Li
- National Engineering Laboratory for Tree Breeding, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- *Correspondence: Zhonghai Li,
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