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Bai S, Liang J, Long T, Liang C, Zhou J, Ge W, Huang B, Lan Y, Zhao J, Long Y. An efficient approach to detect and track winter flush growth of litchi tree based on UAV remote sensing and semantic segmentation. FRONTIERS IN PLANT SCIENCE 2023; 14:1307492. [PMID: 38098788 PMCID: PMC10720909 DOI: 10.3389/fpls.2023.1307492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 11/13/2023] [Indexed: 12/17/2023]
Abstract
The immature winter flush affects the flower bud differentiation, flowering and fruit of litchi, and then seriously reduces the yield of litchi. However, at present, the area estimation and growth process monitoring of winter flush still rely on manual judgment and operation, so it is impossible to accurately and effectively control flush. An efficient approach is proposed in this paper to detect the litchi flush from the unmanned aerial vehicle (UAV) remoting images of litchi crown and track winter flush growth of litchi tree. The proposed model is constructed based on U-Net network, of which the encoder is replaced by MobeilNetV3 backbone network to reduce model parameters and computation. Moreover, Convolutional Block Attention Module (CBAM) is integrated and convolutional layer is added to enhance feature extraction ability, and transfer learning is adopted to solve the problem of small data volume. As a result, the Mean Pixel Accuracy (MPA) and Mean Intersection over Union (MIoU) on the flush dataset are increased from 90.95% and 83.3% to 93.4% and 85%, respectively. Moreover, the size of the proposed model is reduced by 15% from the original model. In addition, the segmentation model is applied to the tracking of winter flushes on the canopy of litchi trees and investigating the two growth processes of litchi flushes (late-autumn shoots growing into flushes and flushes growing into mature leaves). It is revealed that the growth processes of flushes in a particular branch region can be quantitatively analysed based on the UAV images and the proposed semantic segmentation model. The results also demonstrate that a sudden drop in temperature can promote the rapid transformation of late-autumn shoots into flushes. The method proposed in this paper provide a new technique for accurate management of litchi flush and a possibility for the area estimation and growth process monitoring of winter flush, which can assist in the control operation and yield prediction of litchi orchards.
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Affiliation(s)
- Shudai Bai
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
| | - Juntao Liang
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
| | - Teng Long
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
| | - Changjiang Liang
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
| | - Jinxin Zhou
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
| | - Weiyi Ge
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
| | - Binshan Huang
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
| | - Yubin Lan
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
- Country Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
| | - Jing Zhao
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
| | - Yongbing Long
- College of Electronic Engineering/College of Artificial Intelligence, South China Agricultural University, Guangzhou, China
- National Center for International Collaboration Research on Precision Agricultural Aviation Pesticides Spraying Technology, Guangzhou, China
- Country Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China
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Lu X, Lü P, Liu H, Chen H, Pan X, Liu P, Feng L, Zhong S, Zhou B. Identification of Chilling Accumulation-Associated Genes for Litchi Flowering by Transcriptome-Based Genome-Wide Association Studies. FRONTIERS IN PLANT SCIENCE 2022; 13:819188. [PMID: 35283888 PMCID: PMC8905319 DOI: 10.3389/fpls.2022.819188] [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: 11/21/2021] [Accepted: 01/24/2022] [Indexed: 06/14/2023]
Abstract
Litchi is an important Sapindaceae fruit tree. Flowering in litchi is triggered by low temperatures in autumn and winter. It can be divided into early-, medium-, and late-flowering phenotypes according to the time for floral induction. Early-flowering varieties need low chilling accumulation level for floral induction, whereas the late-flowering varieties require high chilling accumulation level. In the present study, RNA-Seq of 87 accessions was performed and transcriptome-based genome-wide association studies (GWAS) was used to identify candidate genes involved in chilling accumulation underlying the time for floral induction. A total of 98,155 high-quality single-nucleotide polymorphism (SNP) sites were obtained. A total of 1,411 significantly associated SNPs and 1,115 associated genes (AGs) were identified, of which 31 were flowering-related, 23 were hormone synthesis-related, and 27 were hormone signal transduction-related. Association analysis between the gene expression of the AGs and the flowering phenotypic data was carried out, and differentially expressed genes (DEGs) in a temperature-controlled experiment were obtained. As a result, 15 flowering-related candidate AGs (CAGs), 13 hormone synthesis-related CAGs, and 11 hormone signal transduction-related CAGs were further screened. The expression levels of the CAGs in the early-flowering accessions were different from those in the late-flowering ones, and also between the flowering trees and non-flowering trees. In a gradient chilling treatment, flowering rates of the trees and the CAGs expression were affected by the treatment. Our present work for the first time provided candidate genes for genetic regulation of flowering in litchi using transcriptome-based GWAS.
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Affiliation(s)
- Xingyu Lu
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
- College of Life and Health Science, Kaili University, Kaili, China
| | - Peitao Lü
- College of Horticulture, Fujian Agriculture and Forestry University-University of California Riverside (FAFU-UCR) Joint Center for Horticultural Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Hao Liu
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Houbin Chen
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Xifen Pan
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Pengxu Liu
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Lei Feng
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Silin Zhong
- State Key Laboratory of Agrobiotechnology, School of Life Sciences, Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Biyan Zhou
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
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Zakaria NI, Ismail MR, Awang Y, Megat Wahab PE, Berahim Z. Effect of Root Restriction on the Growth, Photosynthesis Rate, and Source and Sink Relationship of Chilli ( Capsicum annuum L.) Grown in Soilless Culture. BIOMED RESEARCH INTERNATIONAL 2020; 2020:2706937. [PMID: 32090071 PMCID: PMC7008264 DOI: 10.1155/2020/2706937] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 07/08/2019] [Accepted: 08/09/2019] [Indexed: 11/17/2022]
Abstract
Chilli (Capsicum annum L.) plant is a high economic value vegetable in Malaysia, cultivated in soilless culture containers. In soilless culture, the adoption of small container sizes to optimize the volume of the growing substrate could potentially reduce the production cost, but will lead to a reduction of plant growth and yield. By understanding the physiological mechanism of the growth reduction, several potential measures could be adopted to improve yield under restricted root conditions. The mechanism of growth reduction of plants subjected to root restriction remains unclear. This study was conducted to determine the physiological mechanism of growth reduction of root-restricted chilli plants grown in polyvinyl-chloride (PVC) column of two different volumes, 2392 cm3(root-restricted) and 9570 cm3(control) in soilless culture. Root restriction affected plant growth, physiological process, and yield of chilli plants. Root restriction reduced the photosynthesis rate and photochemical activity of PSII, and increased relative chlorophyll content. Limited root growth in root restriction caused an accumulation of high levels of sucrose in the stem and suggested a transition of the stem as a major sink organ for photoassimilate. Growth reduction in root restriction was not related to limited carbohydrate production, but due to the low sink demand from the roots. Reduction of the total yield per plant about, 23% in root restriction was concomitant, with a slightly increased harvest index which reflected an increased photoassimilate partitioning to the fruit production and suggested more efficient fruits production in the given small plant size of root restriction.
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Affiliation(s)
- Nurul Idayu Zakaria
- Laboratory of Climate-Smart Food Crop Production, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Mohd Razi Ismail
- Laboratory of Climate-Smart Food Crop Production, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
- Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Yahya Awang
- Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Puteri Edaroyati Megat Wahab
- Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
| | - Zulkarami Berahim
- Laboratory of Climate-Smart Food Crop Production, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
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Wu ZC, Zhang JQ, Zhao JT, Li JG, Huang XM, Wang HC. Biosynthesis of quebrachitol, a transportable photosynthate, in Litchi chinensis. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1649-1661. [PMID: 29281092 PMCID: PMC5889025 DOI: 10.1093/jxb/erx483] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Accepted: 12/15/2017] [Indexed: 05/31/2023]
Abstract
Although methylated cyclitols constitute a major proportion of the carbohydrates in many plant species, their physiological roles and biosynthetic pathway are largely unknown. Quebrachitol (2-O-methyl-chiro-inositol) is one of the major methylated cyclitols in some plant species. In litchi, quebrachitol represents approximately 50% of soluble sugars in mature leaves and 40% of the total sugars in phloem exudate. In the present study, we identified bornesitol as a transient methylated intermediate of quebrachitol and measured the concentrations of methyl-inositols in different tissues and in tissues subjected to different treatments. 14CO2 feeding and phloem exudate experiments demonstrated that quebrachitol is one of the transportable photosynthates. In contrast to other plant species, the biosynthesis of quebrachitol in litchi is not associated with osmotic stress. High quebrachitol concentrations in tissues of the woody plant litchi might represent a unique carbon metabolic strategy that maintains osmolality under reduced-sucrose conditions. The presence of bornesitol but not ononitol in the leaves indicates a different biosynthetic pathway with pinitol. The biosynthesis of quebrachitol involves the methylation of myo-inositol and the subsequent epimerization of bornesitol. An inositol methyltransferase gene (LcIMT1) responsible for bornesitol biosynthesis was isolated and characterized for the first time, and the biosynthesis pathways of methyl-inositols are discussed.
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Affiliation(s)
- Zi-Chen Wu
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Jie-Qiong Zhang
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Jie-Tang Zhao
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Jian-Guo Li
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Xu-Ming Huang
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
| | - Hui-Cong Wang
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou, China
- Department of Life Sciences and Technology, Yangtze Normal University, Fuling, China
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Hu Y, Zhang Y, Yu W, Hänninen H, Song L, Du X, Zhang R, Wu J. Novel Insights into the Influence of Seed Sarcotesta Photosynthesis on Accumulation of Seed Dry Matter and Oil Content in Torreya grandis cv. "Merrillii". FRONTIERS IN PLANT SCIENCE 2018; 8:2179. [PMID: 29375592 PMCID: PMC5767305 DOI: 10.3389/fpls.2017.02179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/12/2017] [Indexed: 05/10/2023]
Abstract
Seed oil content is an important trait of nut seeds, and it is affected by the import of carbon from photosynthetic sources. Although green leaves are the main photosynthetic organs, seed sarcotesta photosynthesis also supplies assimilates to seed development. Understanding the relationship between seed photosynthesis and seed development has theoretical and practical significance in the cultivation of Torreya grandis cv. "Merrillii." To assess the role of seed sarcotesta photosynthesis on the seed development, anatomical and physiological traits of sarcotesta were measured during two growing seasons in the field. Compared with the attached current-year leaves, the sarcotesta had higher gross photosynthetic rate at the first stage of seed development. At the late second stage of seed development, sarcotesta showed down-regulation of PSII activity, as indicated by significant decrease in the following chlorophyll fluorescence parameters: the maximum PSII efficiency (Fv/Fm ), the PSII quantum yield (Φ PSII ), and the photosynthetic quenching coefficient (qP). The ribulose 1, 5-bisphosphate carboxylase (Rubisco) activity, the total chlorophyll content (Chl(a+b)) and nitrogen content in the sarcotesta were also significantly decreased during that period. Treatment with DCMU [3-(3,4-dichlorophenyl)-1,1-dimethylurea] preventing seed photosynthesis decreased the seed dry weight and the oil content by 25.4 and 25.5%, respectively. We conclude that seed photosynthesis plays an important role in the dry matter accumulation at the first growth stage. Our results also suggest that down-regulation of seed photosynthesis is a plant response to re-balance the source-sink ratio at the second growth stage. These results suggest that seed photosynthesis is important for biomass accumulation and oil synthesis of the Torreya seeds. The results will facilitate achieving higher yields and oil contents in nut trees by selection for higher seed photosynthesis cultivars.
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Affiliation(s)
- Yuanyuan Hu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, China
| | - Yongling Zhang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, China
| | - Weiwu Yu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, China
| | - Heikki Hänninen
- State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, China
| | - Lili Song
- State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, China
| | - Xuhua Du
- Key Laboratory of High Efficient Processing of Bamboo of Zhejiang Province, China National Bamboo Research Center, Hangzhou, China
| | - Rui Zhang
- State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, China
| | - Jiasheng Wu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A & F University, Hangzhou, China
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Zhang H, Li H, Lai B, Xia H, Wang H, Huang X. Morphological Characterization and Gene Expression Profiling during Bud Development in a Tropical Perennial, Litchi chinensis Sonn. FRONTIERS IN PLANT SCIENCE 2016; 7:1517. [PMID: 27833615 PMCID: PMC5080376 DOI: 10.3389/fpls.2016.01517] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 09/26/2016] [Indexed: 05/11/2023]
Abstract
Tropical evergreen perennials undergo recurrent flush growth, and their terminal buds alternate between growth and dormancy. In sharp contrast to the intensive studies on bud development in temperate deciduous trees, there is little information about bud development regulation in tropical trees. In this study, litchi (Litchi chinensis Sonn.) was used as a model tropical perennial for morphological characterization and transcriptomic analysis of bud development. Litchi buds are naked with apical meristem embraced by rudimentary leaves, which are brown at dormant stage (Stage I). They swell and turn greenish as buds break (Stage II), and as growth accelerates, the rudimentary leaves elongate and open exposing the inner leaf primodia. With the outgrowth of the needle-like leaflets, bud growth reaches a maximum (Stage III). When leaflets expand, bud growth cease with the abortion of the rudimentary leaves at upper positions (Stage IV). Then buds turn brown and reenter dormant status. Budbreak occurs again when new leaves become hard green. Buds at four stages (Stage I to IV) were collected for respiration measurements and in-depth RNA sequencing. Respiration rate was the lowest at Stage I and highest at Stage II, decreasing toward growth cessation. RNA sequencing obtained over 5 Gb data from each of the bud samples and de novo assembly generated a total of 59,999 unigenes, 40,119 of which were annotated. Pair-wise comparison of gene expression between stages, gene profiling across stages, GO/KEGG enrichment analysis, and the expression patterns of 17 major genes highlighted by principal component (PC) analysis displayed significant changes in stress resistance, hormone signal pathways, circadian rhythm, photosynthesis, cell division, carbohydrate metabolism, programmed cell death during bud development, which might be under epigenetic control involving chromatin methylation. The qPCR results of 8 selected unigenes with high PC scores agreed with the RPKM values obtained from RNA-seq. Three Short Vegetative Phase (SVP) genes, namely LcSVP1, LcSVP2, and LcSVP3 displayed different expression patterns, suggesting their differential roles in bud development regulation. The study brought an understanding about biological processes associated with the phase transitions, molecular regulation of bud development, as well as cyclic bud growth as a strategy to survive tropical conditions.
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Affiliation(s)
- Huifen Zhang
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural UniversityGuangzhou, China
| | - Hua Li
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural UniversityGuangzhou, China
| | - Biao Lai
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural UniversityGuangzhou, China
| | - Haoqiang Xia
- Gene Denovo Biotechnology Co. Ltd.Guangzhou, China
| | - Huicong Wang
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural UniversityGuangzhou, China
| | - Xuming Huang
- Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural UniversityGuangzhou, China
- *Correspondence: Xuming Huang
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Sawicki M, Jacquens L, Baillieul F, Clément C, Vaillant-Gaveau N, Jacquard C. Distinct regulation in inflorescence carbohydrate metabolism according to grapevine cultivars during floral development. PHYSIOLOGIA PLANTARUM 2015; 154:447-467. [PMID: 25585972 DOI: 10.1111/ppl.12321] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 12/08/2014] [Accepted: 12/17/2014] [Indexed: 06/04/2023]
Abstract
Carbohydrate metabolism is important in plant sexual reproduction because sugar contents are determining factors for both flower initiation and floral organ development. In woody plants, flowering represents the most energy-consuming step crucial to reproductive success. Nevertheless, in these species, the photosynthesis performed by flowers supplies the carbon required for reproduction. In grapevine (Vitis vinifera), the inflorescence has a specific status because this organ imports carbohydrates at the same time as it exports photoassimilates. In this study, fluctuations in carbohydrate metabolism were monitored by analyzing gas exchanges, photosynthetic electron transport capacity, carbohydrate contents and some activities of carbohydrate metabolism enzymes, in the inflorescences of Pinot noir and Gewurztraminer, two cultivars with a different sensitivity to coulure phenomenon. Our results showed that photosynthetic activity and carbohydrate metabolism are clearly different and differently regulated during the floral development in the two cultivars. Indeed, the regulation of the linear electron flow and the cyclic electron flow is not similar. Moreover, the regulation of PSII activity, with a higher Y(NPQ)/Y(NO) ratio in Gewurztraminer, can be correlated with the higher protection of the photosynthetic chain and consequently with the higher yield under optimal conditions of this cultivar. At least, our results showed a higher photosynthetic activity and a better protection of PSI in Pinot noir during the floral development.
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Affiliation(s)
- Mélodie Sawicki
- Laboratoire de Stress, Défenses et Reproduction des Plantes, UPRES EA4707, Université de Reims Champagne-Ardenne, UFR Sciences, Reims, France
| | - Lucile Jacquens
- Laboratoire de Stress, Défenses et Reproduction des Plantes, UPRES EA4707, Université de Reims Champagne-Ardenne, UFR Sciences, Reims, France
| | - Fabienne Baillieul
- Laboratoire de Stress, Défenses et Reproduction des Plantes, UPRES EA4707, Université de Reims Champagne-Ardenne, UFR Sciences, Reims, France
| | - Christophe Clément
- Laboratoire de Stress, Défenses et Reproduction des Plantes, UPRES EA4707, Université de Reims Champagne-Ardenne, UFR Sciences, Reims, France
| | - Nathalie Vaillant-Gaveau
- Laboratoire de Stress, Défenses et Reproduction des Plantes, UPRES EA4707, Université de Reims Champagne-Ardenne, UFR Sciences, Reims, France
| | - Cédric Jacquard
- Laboratoire de Stress, Défenses et Reproduction des Plantes, UPRES EA4707, Université de Reims Champagne-Ardenne, UFR Sciences, Reims, France
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Li C, Wang Y, Huang X, Li J, Wang H, Li J. De novo assembly and characterization of fruit transcriptome in Litchi chinensis Sonn and analysis of differentially regulated genes in fruit in response to shading. BMC Genomics 2013; 14:552. [PMID: 23941440 PMCID: PMC3751308 DOI: 10.1186/1471-2164-14-552] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 08/09/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Litchi (Litchi chinensis Sonn.) is one of the most important fruit trees cultivated in tropical and subtropical areas. However, a lack of transcriptomic and genomic information hinders our understanding of the molecular mechanisms underlying fruit set and fruit development in litchi. Shading during early fruit development decreases fruit growth and induces fruit abscission. Here, high-throughput RNA sequencing (RNA-Seq) was employed for the de novo assembly and characterization of the fruit transcriptome in litchi, and differentially regulated genes, which are responsive to shading, were also investigated using digital transcript abundance(DTA)profiling. RESULTS More than 53 million paired-end reads were generated and assembled into 57,050 unigenes with an average length of 601 bp. These unigenes were annotated by querying against various public databases, with 34,029 unigenes found to be homologous to genes in the NCBI GenBank database and 22,945 unigenes annotated based on known proteins in the Swiss-Prot database. In further orthologous analyses, 5,885 unigenes were assigned with one or more Gene Ontology terms, 10,234 hits were aligned to the 24 Clusters of Orthologous Groups classifications and 15,330 unigenes were classified into 266 Kyoto Encyclopedia of Genes and Genomes pathways. Based on the newly assembled transcriptome, the DTA profiling approach was applied to investigate the differentially expressed genes related to shading stress. A total of 3.6 million and 3.5 million high-quality tags were generated from shaded and non-shaded libraries, respectively. As many as 1,039 unigenes were shown to be significantly differentially regulated. Eleven of the 14 differentially regulated unigenes, which were randomly selected for more detailed expression comparison during the course of shading treatment, were identified as being likely to be involved in the process of fruitlet abscission in litchi. CONCLUSIONS The assembled transcriptome of litchi fruit provides a global description of expressed genes in litchi fruit development, and could serve as an ideal repository for future functional characterization of specific genes. The DTA analysis revealed that more than 1000 differentially regulated unigenes respond to the shading signal, some of which might be involved in the fruitlet abscission process in litchi, shedding new light on the molecular mechanisms underlying organ abscission.
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Affiliation(s)
- Caiqin Li
- China Litchi Research Center, South China Agricultural University, Guangzhou 510642, China
| | - Yan Wang
- China Litchi Research Center, South China Agricultural University, Guangzhou 510642, China
| | - Xuming Huang
- China Litchi Research Center, South China Agricultural University, Guangzhou 510642, China
| | - Jiang Li
- Beijing Genomics Institute at Shenzhen, Shenzhen 518083, China
| | - Huicong Wang
- China Litchi Research Center, South China Agricultural University, Guangzhou 510642, China
| | - Jianguo Li
- China Litchi Research Center, South China Agricultural University, Guangzhou 510642, China
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McFadyen LM, Robertson D, Sedgley M, Kristiansen P, Olesen T. Post-pruning shoot growth increases fruit abscission and reduces stem carbohydrates and yield in macadamia. ANNALS OF BOTANY 2011; 107:993-1001. [PMID: 21325025 PMCID: PMC3080616 DOI: 10.1093/aob/mcr026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Revised: 11/05/2010] [Accepted: 01/04/2011] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS There is good evidence for deciduous trees that competition for carbohydrates from shoot growth accentuates early fruit abscission and reduces yield but the effect for evergreen trees is not well defined. Here, whole-tree tip-pruning at anthesis is used to examine the effect of post-pruning shoot development on fruit abscission in the evergreen subtropical tree macadamia (Macadamia integrifolia, M. integrifolia × tetraphylla). Partial-tree tip-pruning is also used to test the localization of the effect. METHODS In the first experiment (2005/2006), all branches on trees were tip-pruned at anthesis, some trees were allowed to re-shoot (R treatment) and shoots were removed from others (NR treatment). Fruit set and stem total non-structural carbohydrates (TNSC) over time, and yield were measured. In the second experiment (2006/2007), upper branches of trees were tip-pruned at anthesis, some trees were allowed to re-shoot (R) and shoots were removed from others (NR). Fruit set and yield were measured separately for upper (pruned) and lower (unpruned) branches. KEY RESULTS In the first experiment, R trees set far fewer fruit and had lower yield than NR trees. TNSC fell and rose in all treatments but the decline in R trees occurred earlier than in NR trees and coincided with early shoot growth and the increase in fruit abscission relative to the other treatments. In the second experiment, fruit abscission on upper branches of R trees increased relative to the other treatments but there was little difference in fruit abscission between treatments on lower branches. CONCLUSIONS This study is the first to demonstrate an increase in fruit abscission in an evergreen tree in response to pruning. The effect appeared to be related to competition for carbohydrates between post-pruning shoot growth and fruit development and was local, with shoot growth on pruned branches having no effect on fruit abscission on unpruned branches.
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Affiliation(s)
- Lisa M. McFadyen
- Industry and Investment NSW, Centre for Tropical Horticulture, PO Box 72, Alstonville, NSW 2477, Australia
| | - David Robertson
- Industry and Investment NSW, Centre for Tropical Horticulture, PO Box 72, Alstonville, NSW 2477, Australia
| | - Margaret Sedgley
- The University of New England, Faculty of Arts and Sciences, Armidale, NSW 2351, Australia
| | - Paul Kristiansen
- The University of New England, Faculty of Arts and Sciences, Armidale, NSW 2351, Australia
| | - Trevor Olesen
- Industry and Investment NSW, Centre for Tropical Horticulture, PO Box 72, Alstonville, NSW 2477, Australia
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Alcaraz ML, Hormaza JI, Rodrigo J. Ovary starch reserves and pistil development in avocado (Persea americana). PHYSIOLOGIA PLANTARUM 2010; 140:395-404. [PMID: 20849425 DOI: 10.1111/j.1399-3054.2010.01410.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In avocado, only a very small fraction of the flowers are able to set fruit. Previous work in other woody perennial plant species has shown the importance of carbohydrates accumulated in the flower in the reproductive process. Thus, in order to explore the implications of the nutritive status of the flower in the reproductive process in avocado, the starch content in the pistil has been examined in individual pollinated and non-pollinated flowers at anthesis and during the days following anthesis. Starch content in different pistilar tissues in each flower was quantified with the help of an image analysis system attached to a microscope. Flowers at anthesis were rich in highly compartmentalized starch. Although no external morphological differences could be observed among flowers, the starch content varied widely at flower opening. Starch content in the ovary is largely independent of flower size because these differences were not correlated with ovary size. Differences in the progress of starch accumulation within the ovule integuments between pollinated and non-pollinated flowers occurred concomitantly with the triggering of the progamic phase. The results suggest that starch reserves in the ovary could play a significant role in the reproductive process in avocado.
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Affiliation(s)
- M Librada Alcaraz
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Consejo Superior de Investigaciones Científicas, 29750 Algarrobo-Costa, Málaga, Spain
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