1
|
Ma X, Dai S, Qin N, Zhu C, Qin J, Li J. Genome-wide identification and expression analysis of the SAUR gene family in foxtail millet (Setaria italica L.). BMC Plant Biol 2023; 23:31. [PMID: 36639742 PMCID: PMC9840322 DOI: 10.1186/s12870-023-04055-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND Auxin performs important functions in plant growth and development processes, as well as abiotic stress. Small auxin-up RNA (SAUR) is the largest gene family of auxin-responsive factors. However, the knowledge of the SAUR gene family in foxtail millet is largely obscure. RESULTS In the current study, 72 SiSAUR genes were identified and renamed according to their chromosomal distribution in the foxtail millet genome. These SiSAUR genes were unevenly distributed on nine chromosomes and were classified into three groups through phylogenetic tree analysis. Most of the SiSAUR members from the same group showed similar gene structure and motif composition characteristics. Analysis of cis-acting elements showed that many hormone and stress response elements were identified in the promoter region of SiSAURs. Gene replication analysis revealed that many SiSAUR genes were derived from gene duplication events. We also found that the expression of 10 SiSAURs was induced by abiotic stress and exogenous hormones, which indicated that SiSAUR genes may participated in complex physiological processes. CONCLUSIONS Overall, these results will be valuable for further studies on the biological role of SAUR genes in foxtail development and response to stress conditions and may shed light on the improvement of the genetic breeding of foxtail millet.
Collapse
Affiliation(s)
- Xiaoqian Ma
- College of Agriculture, Henan University of Science and Technology, Luoyang, 471000, Henan, People's Republic of China
| | - Shutao Dai
- Henan Academy of Agriculture Sciences, Cereal Crops Institute, Zhengzhou, 450002, Henan, People's Republic of China
| | - Na Qin
- Henan Academy of Agriculture Sciences, Cereal Crops Institute, Zhengzhou, 450002, Henan, People's Republic of China
| | - Cancan Zhu
- Henan Academy of Agriculture Sciences, Cereal Crops Institute, Zhengzhou, 450002, Henan, People's Republic of China
| | - Jiafan Qin
- Luoyang Academy of Agriculture and Forestry Sciences, Sweet Potato and Millet Institute, , Luoyang, 471023, Henan, People's Republic of China
| | - Junxia Li
- Henan Academy of Agriculture Sciences, Cereal Crops Institute, Zhengzhou, 450002, Henan, People's Republic of China.
| |
Collapse
|
2
|
Li M, Chen R, Gu H, Cheng D, Guo X, Shi C, Li L, Xu G, Gu S, Wu Z, Chen J. Grape Small Auxin Upregulated RNA ( SAUR) 041 Is a Candidate Regulator of Berry Size in Grape. Int J Mol Sci 2021; 22:ijms222111818. [PMID: 34769249 PMCID: PMC8584205 DOI: 10.3390/ijms222111818] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/29/2021] [Accepted: 10/29/2021] [Indexed: 11/25/2022] Open
Abstract
Grape (Vitis vinifera) is an important horticultural crop that can be used to make juice and wine. However, the small size of the berry limits its yield. Cultivating larger berry varieties can be an effective way to solve this problem. As the largest family of auxin early response genes, SAUR (small auxin upregulated RNA) plays an important role in the growth and development of plants. Berry size is one of the important factors that determine grape quality. However, the SAUR gene family’s function in berry size of grape has not been studied systematically. We identified 60 SAUR members in the grape genome and divided them into 12 subfamilies based on phylogenetic analysis. Subsequently, we conducted a comprehensive and systematic analysis on the SAUR gene family by analyzing distribution of key amino acid residues in the domain, structural features, conserved motifs, and protein interaction network, and combined with the heterologous expression in Arabidopsis and tomato. Finally, the member related to grape berry size in SAUR gene family were screened. This genome-wide study provides a systematic analysis of grape SAUR gene family, further understanding the potential functions of candidate genes, and provides a new idea for grape breeding.
Collapse
Affiliation(s)
- Ming Li
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Rui Chen
- Biotechnology Research Institute, Tianjin Academy of Agricultural Sciences, Tianjin 300192, China;
| | - Hong Gu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Dawei Cheng
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Xizhi Guo
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Caiyun Shi
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Lan Li
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Guoyi Xu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Shicao Gu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Zhiyong Wu
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
| | - Jinyong Chen
- Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China; (M.L.); (H.G.); (D.C.); (X.G.); (C.S.); (L.L.); (G.X.); (S.G.); (Z.W.)
- Correspondence:
| |
Collapse
|
3
|
Xu YX, Xiao MZ, Liu Y, Fu JL, He Y, Jiang DA. The small auxin-up RNA OsSAUR45 affects auxin synthesis and transport in rice. Plant Mol Biol 2017; 94:97-107. [PMID: 28321650 DOI: 10.1007/s11103-017-0595-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 02/16/2017] [Indexed: 05/25/2023]
Abstract
This research is the first to demonstrate that OsSAUR45 is involved in plant growth though affecting auxin synthesis and transport by repressing OsYUCCA and OsPIN gene expression in rice. Small auxin-up RNAs (SAURs) comprise a large multigene family and are rapidly activated as part of the primary auxin response in plants. However, little is known about the role of SAURs in plant growth and development, especially in monocots. Here, we report the biological function of OsSAUR45 in the model plant rice (Oryza sativa). OsSAUR45 is expressed in a tissue-specific pattern and is localized to the cytoplasm. Rice lines overexpressing OsSAUR45 displayed pleiotropic developmental defects including reduced plant height and primary root length, fewer adventitious roots, narrower leaves, and reduced seed setting. Auxin levels and transport were reduced in the OsSAUR45 overexpression lines, potentially because of decreased expression of Flavin-binding monooxygenase family proteins (OsYUCCAs) and PIN-FORMED family proteins (OsPINs). Exogenous auxin application rapidly induced OsSAUR45 expression and partially restored the phenotype of rice lines overexpressing OsSAUR45. These results demonstrate that OsSAUR45 is involved in plant growth by affecting auxin synthesis and transport through the repression of OsYUCCA and OsPIN gene expression in rice.
Collapse
Affiliation(s)
- Yan-Xia Xu
- National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Sciences/Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou, 310008, China.
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
| | - Meng-Zhu Xiao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yan Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Jun-Liang Fu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Yi He
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - De-An Jiang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
4
|
Bai Q, Hou D, Li L, Cheng Z, Ge W, Liu J, Li X, Mu S, Gao J. Genome-wide analysis and expression characteristics of small auxin-up RNA (SAUR) genes in moso bamboo (Phyllostachys edulis). Genome 2016; 60:325-336. [PMID: 28177844 DOI: 10.1139/gen-2016-0097] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Moso bamboo (Phyllostachys edulis) is well known for its rapid shoot growth. Auxin exerts pleiotropic effects on plant growth. The small auxin-up RNA (SAUR) genes are early auxin-responsive genes involved in plant growth. In total, 38 SAUR genes were identified in P. edulis (PheSAUR). A comprehensive overview of the PheSAUR gene family is presented, including the gene structures, phylogeny, and subcellular location predictions. A transcriptome analysis indicated that 37 (except PheSAUR18) of the PheSAUR genes were expressed during shoot growth process and that the PheSAUR genes were differentially expressed. Furthermore, quantitative real-time PCR analysis indicated that all of the PheSAUR genes could be induced in different tissues of seedlings and that 37 (except PheSAUR41) of the PheSAUR genes were up-regulated after indole-3-acetic acid (IAA) treatment. These results reveal a comprehensive overview of the PheSAUR gene family and may pave the way for deciphering their functions during bamboo development.
Collapse
Affiliation(s)
- Qingsong Bai
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| | - Dan Hou
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| | - Long Li
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| | - Zhanchao Cheng
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| | - Wei Ge
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| | - Jun Liu
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| | - Xueping Li
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| | - Shaohua Mu
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| | - Jian Gao
- International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China.,International Center for Bamboo and Rattan, Key Laboratory of Bamboo and Rattan Science and Technology, State Forestry Administration, Beijing, People's Republic of China
| |
Collapse
|
5
|
HUANG XING, BAO YANING, WANG BO, LIU LIJUN, CHEN JIE, DAI LUNJIN, BALOCH SANAULLAH, PENG DINGXIANG. Identification of small auxin-up RNA (SAUR) genes in Urticales plants: mulberry (Morus notabilis), hemp (Cannabis sativa) and ramie (Boehmeria nivea). J Genet 2016; 95:119-29. [DOI: 10.1007/s12041-016-0622-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
6
|
Ren H, Gray WM. SAUR Proteins as Effectors of Hormonal and Environmental Signals in Plant Growth. Mol Plant 2015; 8:1153-64. [PMID: 25983207 PMCID: PMC5124491 DOI: 10.1016/j.molp.2015.05.003] [Citation(s) in RCA: 264] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Revised: 05/05/2015] [Accepted: 05/05/2015] [Indexed: 05/18/2023]
Abstract
The plant hormone auxin regulates numerous aspects of plant growth and development. Early auxin response genes mediate its genomic effects on plant growth and development. Discovered in 1987, small auxin up RNAs (SAURs) are the largest family of early auxin response genes. SAUR functions have remained elusive, however, presumably due to extensive genetic redundancy. However, recent molecular, genetic, biochemical, and genomic studies have implicated SAURs in the regulation of a wide range of cellular, physiological, and developmental processes. Recently, crucial mechanistic insight into SAUR function was provided by the demonstration that SAURs inhibit PP2C.D phosphatases to activate plasma membrane (PM) H(+)-ATPases and promote cell expansion. In addition to auxin, several other hormones and environmental factors also regulate SAUR gene expression. We propose that SAURs are key effector outputs of hormonal and environmental signals that regulate plant growth and development.
Collapse
Affiliation(s)
- Hong Ren
- Department of Plant Biology, University of Minnesota, 250 Biological Sciences Center, 1445 Gortner Avenue, St. Paul, MN 55108, USA
| | - William M Gray
- Department of Plant Biology, University of Minnesota, 250 Biological Sciences Center, 1445 Gortner Avenue, St. Paul, MN 55108, USA.
| |
Collapse
|
7
|
Priya R, Siva R. Analysis of phylogenetic and functional diverge in plant nine-cis epoxycarotenoid dioxygenase gene family. J Plant Res 2015; 128:519-34. [PMID: 25929830 DOI: 10.1007/s10265-015-0726-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/15/2014] [Indexed: 05/27/2023]
Abstract
During different environmental stress conditions, plant growth is regulated by the hormone abscisic acid (an apocarotenoid). In the biosynthesis of abscisic acid, the oxidative cleavage of cis-epoxycarotenoid catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED) is the crucial step. The NCED genes were isolated in numerous plant species and those genes were phylogenetically investigated to understand the evolution of NCED genes in various plant lineages comprising lycophyte, gymnosperm, dicot and monocot. A total of 93 genes were obtained from 48 plant species to statistically estimate their sequence conservation and functional divergence. Selaginella moellendorffii appeared to be evolutionarily distinct from those of the angiosperms, insisting the substantial influence of natural selection pressure on NCED genes. Further, using exon-intron structure analysis, the gene structures of NCED were found to be conserved across some species. In addition, the substitution rate ratio of non-synonymous (Ka) versus synonymous (Ks) mutations using the Bayesian inference approach, depicted the critical amino acid residues for functional divergence. A significant functional divergence was found between some subgroups through the co-efficient of type-I functional divergence. Our results suggest that the evolution of NCED genes occurred by duplication, diversification and exon intron loss events. The site-specific profile and functional diverge analysis revealed NCED genes might facilitate the tissue-specific functional divergence in NCED sub-families, that could combat different environmental stress conditions aiding plant survival.
Collapse
Affiliation(s)
- R Priya
- School of Bio Sciences and Technology, VIT University, Vellore, 632014, Tamil Nadu, India
| | | |
Collapse
|
8
|
Abstract
Although a number of plant carotenoid cleavage dioxygenase (CCD) genes have been functionally characterized in different plant species, little is known about the biochemical role and enzymatic activities of members of the subclass 4 (CCD4). To gain insight into their biological function, CCD4 genes were isolated from apple (Malus x domestica, MdCCD4), chrysanthemum (Chrysanthemum x morifolium, CmCCD4a), rose (Rosa x damascena, RdCCD4), and osmanthus (Osmanthus fragrans, OfCCD4), and were expressed, together with AtCCD4, in Escherichia coli. In vivo assays showed that CmCCD4a and MdCCD4 cleaved beta-carotene well to yield beta-ionone, while OfCCD4, RdCCD4, and AtCCD4 were almost inactive towards this substrate. No cleavage products were found for any of the five CCD4 genes when they were co-expressed in E. coli strains that accumulated cis-zeta-carotene and lycopene. In vitro assays, however, demonstrated the breakdown of 8'-apo-beta-caroten-8'-al by AtCCD4 and RdCCD4 to beta-ionone, while this apocarotenal was almost not degraded by OfCCD4, CmCCD4a, and MdCCD4. Sequence analysis of genomic clones of CCD4 genes revealed that RdCCD4, like AtCCD4, contains no intron, while MdCCD, OfCCD4, and CmCCD4a contain introns. These results indicate that plants produce at least two different forms of CCD4 proteins. Although CCD4 enzymes cleave their substrates at the same position (9,10 and 9',10'), they might have different biochemical functions as they accept different (apo)-carotenoid substrates, show various expression patterns, and are genomically differently organized.
Collapse
Affiliation(s)
- Fong-Chin Huang
- Biomolecular Food Technology, Technische Universität München, Hochfeldweg 1, D-85354 Freising, Germany
| | - Péter Molnár
- University of Pécs, Medical School Department of Pharmacognosy, H-7624 Pécs, Rókus u. 2, Hungary
| | - Wilfried Schwab
- Biomolecular Food Technology, Technische Universität München, Hochfeldweg 1, D-85354 Freising, Germany
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
9
|
Abstract
Bixin, also known as annatto, is a seed-specific pigment widely used in foods and cosmetics since pre-Columbian times. We show that three genes from Bixa orellana, native to tropical America, govern bixin biosynthesis. These genes code for lycopene cleavage dioxygenase, bixin aldehyde dehydrogenase, and norbixin carboxyl methyltransferase, which catalyze the sequential conversion of lycopene into bixin. Introduction of these three genes in Escherichia coli engineered to produce lycopene induced bixin synthesis, thus expanding the supply of this economically important plant product.
Collapse
Affiliation(s)
- Florence Bouvier
- Institut de Biologie Moléculaire des Plantes, CNRS, Université Louis Pasteur, 67084 Strasbourg, Cedex, France
| | | | | |
Collapse
|
10
|
Knauss S, Rohrmeier T, Lehle L. The auxin-induced maize gene ZmSAUR2 encodes a short-lived nuclear protein expressed in elongating tissues. J Biol Chem 2003; 278:23936-43. [PMID: 12695517 DOI: 10.1074/jbc.m212585200] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
By differential screening of a cDNA library from auxin-induced maize coleoptiles we have isolated and characterized a SAUR gene, designated ZmSAUR2, belonging to a not yet characterized subtype of the SAUR family. ZmSAUR2 encodes a 15.3-kDa protein and is specifically induced by auxin in elongating coleoptile tissue but not in primary leaves or in roots. The transcript level rapidly increased within minutes and preceded auxin-stimulated elongation of coleoptile segments. Cycloheximide also induced ZmSAUR2 transcription, as has been shown for other early auxin-induced genes, whereas abscisic acid, brassinolide, ethylene, gibberellic acid, kinetin, and methyl jasmonate did not provoke an increase in ZmSAUR2 mRNA abundance. In pulse-chase experiments using auxin-induced coleoptiles and an anti-ZmSAUR2 antibody we were able to precipitate a protein of the expected molecular mass and to determine a half-life of about 7 min, which is among the shortest known in eukaryotes. In gel shift assays binding of calmodulin to ZmSAUR2 was demonstrated, suggesting the possibility of post-transcriptional regulation. Upon transformation of onion epidermal cells with a ZmSAUR2::GUS construct the corresponding chimeric protein was detected in the nucleus. The results suggest that ZmSAUR2 encodes a short-lived nuclear protein that might be involved in auxin-mediated cell elongation.
Collapse
Affiliation(s)
- Stefan Knauss
- Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
| | | | | |
Collapse
|
11
|
Affiliation(s)
- Ruth R. Finkelstein
- Department of Molecular, Cellular and Developmental Biology, University of California at Santa Barbara, Santa Barbara, CA 93106
- Corresponding author: Telephone: (805) 893-4800, Fax: (805) 893-4724,
| | - Christopher D. Rock
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409-3131
| |
Collapse
|
12
|
Chernys JT, Zeevaart JA. Characterization of the 9-cis-epoxycarotenoid dioxygenase gene family and the regulation of abscisic acid biosynthesis in avocado. Plant Physiol 2000; 124:343-53. [PMID: 10982448 PMCID: PMC59148 DOI: 10.1104/pp.124.1.343] [Citation(s) in RCA: 201] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2000] [Accepted: 05/19/2000] [Indexed: 05/18/2023]
Abstract
Avocado (Persea americana Mill. cv Lula) is a climacteric fruit that exhibits a rise in ethylene as the fruit ripens. This rise in ethylene is followed by an increase in abscisic acid (ABA), with the highest level occurring just after the peak in ethylene production. ABA is synthesized from the cleavage of carotenoid precursors. The cleavage of carotenoid precursors produces xanthoxin, which can subsequently be converted into ABA via ABA-aldehyde. Indirect evidence indicates that the cleavage reaction, catalyzed by 9-cis-epoxycarotenoid dioxygenase (NCED), is the regulatory step in ABA synthesis. Three genes encoding NCED cleavage-like enzymes were cloned from avocado fruit. Two genes, PaNCED1 and PaNCED3, were strongly induced as the fruit ripened. The other gene, PaNCED2, was constitutively expressed during fruit ripening, as well as in leaves. This gene lacks a predicted chloroplast transit peptide. It is therefore unlikely to be involved in ABA biosynthesis. PaNCED1 was induced by water stress, but expression of PaNCED3 was not detectable in dehydrated leaves. Recombinant PaNCED1 and PaNCED3 were capable of in vitro cleavage of 9-cis-xanthophylls into xanthoxin and C(25)-apocarotenoids, but PaNCED2 was not. Taken together, the results indicate that ABA biosynthesis in avocado is regulated at the level of carotenoid cleavage.
Collapse
Affiliation(s)
- J T Chernys
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824-1312, USA
| | | |
Collapse
|
13
|
Abstract
The use of (35)S-labeled calmodulin (CaM) to screen a corn root cDNA expression library has led to the isolation of a CaM-binding protein, encoded by a cDNA with sequence similarity to small auxin up RNAs (SAURs), a class of early auxin-responsive genes. The cDNA designated as ZmSAUR1 (Zea mays SAURs) was expressed in Escherichia coli, and the recombinant protein was purified by CaM affinity chromatography. The CaM binding assay revealed that the recombinant protein binds to CaM in a calcium-dependent manner. Deletion analysis revealed that the CaM binding site was located at the NH(2)-terminal domain. A synthetic peptide of amino acids 20-45, corresponding to the potential CaM binding region, was used for calcium-dependent mobility shift assays. The synthetic peptide formed a stable complex with CaM only in the presence of calcium. The CaM affinity assay indicated that ZmSAUR1 binds to CaM with high affinity (K(d) approximately 15 nM) in a calcium-dependent manner. Comparison of the NH(2)-terminal portions of all of the characterized SAURs revealed that they all contain a stretch of the basic alpha-amphiphilic helix similar to the CaM binding region of ZmSAUR1. CaM binds to the two synthetic peptides from the NH(2)-terminal regions of Arabidopsis SAUR-AC1 and soybean 10A5, suggesting that this is a general phenomenon for all SAURs. Northern analysis was carried out using the total RNA isolated from auxin-treated corn coleoptile segments. ZmSAUR1 gene expression began within 10 min, increased rapidly between 10 and 60 min, and peaked around 60 min after 10 microM alpha-naphthaleneacetic acid treatment. These results indicate that ZmSAUR1 is an early auxin-responsive gene. The CaM antagonist N-(6-aminohexyl)5-chloro-1-naphthalenesulfonamide hydrochloride inhibited the auxin-induced cell elongation but not the auxin-induced expression of ZmSAUR1. This suggests that calcium/CaM do not regulate ZmSAUR1 at the transcriptional level. CaM binding to ZmSAUR1 in a calcium-dependent manner suggests that calcium/CaM regulate ZmSAUR1 at the post-translational level. Our data provide the first direct evidence for the involvement of calcium/CaM-mediated signaling in auxin-mediated signal transduction.
Collapse
Affiliation(s)
- T Yang
- Laboratory of Plant Molecular Biology, Department of Horticulture, Washington State University, Pullman, Washington 99164-6414, USA
| | | |
Collapse
|