1
|
Wang D, Dong X, Zhong MC, Jiang XD, Cui WH, Bendahmane M, Hu JY. Molecular and genetic regulation of petal number variation. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:3233-3247. [PMID: 38546444 DOI: 10.1093/jxb/erae136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/26/2024] [Indexed: 06/11/2024]
Abstract
Floral forms with an increased number of petals, also known as double-flower phenotypes, have been selected and conserved in many domesticated plants, particularly in ornamentals, because of their great economic value. The molecular and genetic mechanisms that control this trait are therefore of great interest, not only for scientists, but also for breeders. In this review, we summarize current knowledge of the gene regulatory networks of flower initiation and development and known mutations that lead to variation of petal number in many species. In addition to the well-accepted miR172/AP2-like module, for which many questions remain unanswered, we also discuss other pathways in which mutations also lead to the formation of extra petals, such as those involved in meristem maintenance, hormone signalling, epigenetic regulation, and responses to environmental signals. We discuss how the concept of 'natural mutants' and recent advances in genomics and genome editing make it possible to explore the molecular mechanisms underlying double-flower formation, and how such knowledge could contribute to the future breeding and selection of this trait in more crops.
Collapse
Affiliation(s)
- Dan Wang
- Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, 650204 Kunming, Yunnan, China
| | - Xue Dong
- Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, 650201 Kunming, Yunnan, China
| | - Mi-Cai Zhong
- Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Xiao-Dong Jiang
- Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Wei-Hua Cui
- Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| | - Mohammed Bendahmane
- Laboratoire Reproduction et Développement des Plantes, INRAE-CNRS-Lyon1-ENS, Ecole Normale Supérieure de Lyon, Lyon, France
| | - Jin-Yong Hu
- Yunnan Key Laboratory of Crop Wild Relatives Omics, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
| |
Collapse
|
2
|
Vicente MH, MacLeod K, Zhu F, Rafael DD, Figueira A, Fernie AR, Mohareb F, Kevei Z, Thompson AJ, Zsögön A, Peres LEP. The ORGAN SIZE (ORG) locus modulates both vegetative and reproductive gigantism in domesticated tomato. ANNALS OF BOTANY 2023; 132:1233-1248. [PMID: 37818893 PMCID: PMC10902882 DOI: 10.1093/aob/mcad150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/29/2023] [Accepted: 10/02/2023] [Indexed: 10/13/2023]
Abstract
BACKGROUND AND AIMS Gigantism is a key component of the domestication syndrome, a suite of traits that differentiates crops from their wild relatives. Allometric gigantism is strongly marked in horticultural crops, causing disproportionate increases in the size of edible parts such as stems, leaves or fruits. Tomato (Solanum lycopersicum) has attracted attention as a model for fruit gigantism, and many genes have been described controlling this trait. However, the genetic basis of a corresponding increase in size of vegetative organs contributing to isometric gigantism has remained relatively unexplored. METHODS Here, we identified a 0.4-Mb region on chromosome 7 in introgression lines (ILs) from the wild species Solanum pennellii in two different tomato genetic backgrounds (cv. 'M82' and cv. 'Micro-Tom') that controls vegetative and reproductive organ size in tomato. The locus, named ORGAN SIZE (ORG), was fine-mapped using genotype-by-sequencing. A survey of the literature revealed that ORG overlaps with previously mapped quantitative trait loci controlling tomato fruit weight during domestication. KEY RESULTS Alleles from the wild species led to lower cell number in different organs, which was partially compensated by greater cell expansion in leaves, but not in fruits. The result was a proportional reduction in leaf, flower and fruit size in the ILs harbouring the alleles from the wild species. CONCLUSIONS Our findings suggest that selection for large fruit during domestication also tends to select for increases in leaf size by influencing cell division. Since leaf size is relevant for both source-sink balance and crop adaptation to different environments, the discovery of ORG could allow fine-tuning of these parameters.
Collapse
Affiliation(s)
- Mateus Henrique Vicente
- Laboratory of Plant Developmental Genetics, Departamento de Ciências Biológicas, Escola Superior de Agricultura ‘Luiz de Queiroz’, Universidade de São Paulo, CP 09, 13418-900, Piracicaba, SP, Brazil
| | - Kyle MacLeod
- Cranfield Soil and AgriFood Institute, Cranfield University, Cranfield, MK43 0AL, UK
| | - Feng Zhu
- Max-Planck-Institute for Molecular Plant Physiology, 14476 Potsdam, Germany
- National R&D Center for Citrus Preservation, Key Laboratory of Horticultural Plant Biology, Ministry of Education, Huazhong Agricultural University, 430070 Wuhan, China
| | - Diego D Rafael
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, MG, Brazil
| | - Antonio Figueira
- Laboratory of Plant Breeding, Centro de Energia Nuclear na Agricultura (CENA), USP, Av. Centenário, 303, 13400-970, Piracicaba, SP, Brazil
| | - Alisdair R Fernie
- Max-Planck-Institute for Molecular Plant Physiology, 14476 Potsdam, Germany
| | - Fady Mohareb
- Cranfield Soil and AgriFood Institute, Cranfield University, Cranfield, MK43 0AL, UK
| | - Zoltan Kevei
- Cranfield Soil and AgriFood Institute, Cranfield University, Cranfield, MK43 0AL, UK
| | - Andrew J Thompson
- Cranfield Soil and AgriFood Institute, Cranfield University, Cranfield, MK43 0AL, UK
| | - Agustin Zsögön
- Max-Planck-Institute for Molecular Plant Physiology, 14476 Potsdam, Germany
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, MG, Brazil
| | - Lázaro Eustáquio Pereira Peres
- Laboratory of Plant Developmental Genetics, Departamento de Ciências Biológicas, Escola Superior de Agricultura ‘Luiz de Queiroz’, Universidade de São Paulo, CP 09, 13418-900, Piracicaba, SP, Brazil
| |
Collapse
|
3
|
Abstract
Fruit-size increase is one of the major changes associated with tomato domestication, and it currently represents an important objective for breeding. Regulatory mutations at the LOCULE NUMBER and FASCIATED loci, the orthologues of the Arabidopsis WUSCHEL and CLAVATA3, have mainly contributed to enlarging fruit size by altering meristem activity. Here, we identify ENO as a tomato fruit regulator, which may function by regulating WUSCHEL gene expression to restrict stem-cell proliferation in a flower-specific manner. Our findings also show that a mutation in the ENO promoter was selected during domestication to establish the background for enhancing fruit size in cultivated tomatoes, denoting that transcriptional changes in key regulators have significant effects on agronomic traits. A dramatic evolution of fruit size has accompanied the domestication and improvement of fruit-bearing crop species. In tomato (Solanum lycopersicum), naturally occurring cis-regulatory mutations in the genes of the CLAVATA-WUSCHEL signaling pathway have led to a significant increase in fruit size generating enlarged meristems that lead to flowers with extra organs and bigger fruits. In this work, by combining mapping-by-sequencing and CRISPR/Cas9 genome editing methods, we isolated EXCESSIVE NUMBER OF FLORAL ORGANS (ENO), an AP2/ERF transcription factor which regulates floral meristem activity. Thus, the ENO gene mutation gives rise to plants that yield larger multilocular fruits due to an increased size of the floral meristem. Genetic analyses indicate that eno exhibits synergistic effects with mutations at the LOCULE NUMBER (encoding SlWUS) and FASCIATED (encoding SlCLV3) loci, two central players in the evolution of fruit size in the domestication of cultivated tomatoes. Our findings reveal that an eno mutation causes a substantial expansion of SlWUS expression domains in a flower-specific manner. In vitro binding results show that ENO is able to interact with the GGC-box cis-regulatory element within the SlWUS promoter region, suggesting that ENO directly regulates SlWUS expression domains to maintain floral stem-cell homeostasis. Furthermore, the study of natural allelic variation of the ENO locus proved that a cis-regulatory mutation in the promoter of ENO had been targeted by positive selection during the domestication process, setting up the background for significant increases in fruit locule number and fruit size in modern tomatoes.
Collapse
|
4
|
Li H, Sun MH, Qi MF, Xing J, Xu T, Liu HT, Li TL. Alteration of SlYABBY2b gene expression impairs tomato ovary locule number and endogenous gibberellin content. J Zhejiang Univ Sci B 2018. [DOI: 10.1631/jzus.b1700238] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
5
|
Ye J, Yang Y, Chen B, Shi J, Luo M, Zhan J, Wang X, Liu G, Wang H. An integrated analysis of QTL mapping and RNA sequencing provides further insights and promising candidates for pod number variation in rapeseed (Brassica napus L.). BMC Genomics 2017; 18:71. [PMID: 28077071 PMCID: PMC5225578 DOI: 10.1186/s12864-016-3402-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 12/09/2016] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND As the most important yield component in rapeseed (Brassica napus L.), pod number is determined by a series of successive growth and development processes. Pod number shows extensive variation in rapeseed natural germplasm, which is valuable for genetic improvement. However, the genetic and especially the molecular mechanism for this kind of variation are poorly understood. In this study, we conducted QTL mapping and RNA sequencing, respectively, using the BnaZNRIL population and its two parental cultivars Zhongshuang11 and No.73290 which showed significant difference in pod number, primarily due to the difference in floral organ number. RESULT A total of eight QTLs for pod number were identified using BnaZNRIL population with a high-density SNP linkage map, each was distributed on seven linkage groups and explained 5.8-11.9% of phenotypic variance. Then, they were integrated with those previously detected in BnaZNF2 population (deriving from same parents) and resulted in 15 consensus-QTLs. Of which, seven QTLs were identical to other studies, whereas the other eight should be novel. RNA sequencing of the shoot apical meristem (SAM) at the formation stage of floral bud primordia identified 9135 genes that were differentially expressed between the two parents. Gene ontology (GO) analysis showed that the top two enriched groups were S-assimilation, providing an essential nutrient for the synthesis of diverse metabolites, and polyamine metabolism, serving as second messengers that play an essential role in flowering genes initiation. KEGG analysis showed that the top three overrepresented pathways were carbohydrate (707 genes), amino acid (390 genes) and lipid metabolisms (322 genes). In silico mapping showed that 647 DEGs were located within the confidence intervals of 15 consensus QTLs. Based on annotations of Arabidopsis homologs corresponding to DEGs, nine genes related to meristem growth and development were considered as promising candidates for six QTLs. CONCLUSION In this study, we discovered the first repeatable major QTL for pod number in rapeseed. In addition, RNA sequencing was performed for SAM in rapeseed, which provides new insights into the determination of floral organ number. Furthermore, the integration of DEGs and QTLs identified promising candidates for further gene cloning and mechanism study.
Collapse
Affiliation(s)
- Jiang Ye
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China
| | - Yuhua Yang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China
| | - Bo Chen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jiaqin Shi
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China.
| | - Meizhong Luo
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jiepeng Zhan
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China
| | - Xinfa Wang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China
| | - Guihua Liu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China
| | - Hanzhong Wang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, China.
| |
Collapse
|
6
|
Li H, Qi M, Sun M, Liu Y, Liu Y, Xu T, Li Y, Li T. Tomato Transcription Factor SlWUS Plays an Important Role in Tomato Flower and Locule Development. FRONTIERS IN PLANT SCIENCE 2017; 8:457. [PMID: 28408915 PMCID: PMC5374213 DOI: 10.3389/fpls.2017.00457] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/15/2017] [Indexed: 05/19/2023]
Abstract
Tomato is a model species for fleshy fruit development. The shapes and sizes of tomato (Solanum lycopersicum L.) are mainly controlled by several loci, including locule number (lc). Two single nucleotide polymorphisms were found downstream of WUSCHEL (SlWUS) in a putative tomato CArG cis-regulatory element. The lc mutation may affect the binding of AGAMOUS(AG), cause the up-regulation of SlWUS and result in increased locule numbers. In this study, tissue expression levels showed that SlWUS is expressed in young floral buds and shoot apexes. Silencing SlWUS on an lc mutant genetic background with an RNA interference (RNAi) strategy resulted in smaller flowers and fruit than those of the wild-type plants, with decreased locule number. Further study revealed that the SlWUS RNAi lines exhibited altered expression levels of the TAG1 and SlCLV3 genes that participate in the regulation of tomato flower and fruit locule development. In conclusion, this study provides the first genetic evidence that SlWUS may be the candidate gene of the lc locus and reveals the function of SlWUS in flower development.
Collapse
Affiliation(s)
- Hui Li
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang Agricultural UniversityShenyang, China
- Collaborative Innovation Center of Protected Vegetable Surround Bohai Gulf RegionShenyang, China
| | - Mingfang Qi
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang Agricultural UniversityShenyang, China
- Collaborative Innovation Center of Protected Vegetable Surround Bohai Gulf RegionShenyang, China
| | - Meihua Sun
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang Agricultural UniversityShenyang, China
- Collaborative Innovation Center of Protected Vegetable Surround Bohai Gulf RegionShenyang, China
| | - Ying Liu
- Liaoyang Academy of Agricultural and Forestry ScienceLiaoyang, China
| | - Yudong Liu
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang Agricultural UniversityShenyang, China
- Collaborative Innovation Center of Protected Vegetable Surround Bohai Gulf RegionShenyang, China
| | - Tao Xu
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang Agricultural UniversityShenyang, China
- Collaborative Innovation Center of Protected Vegetable Surround Bohai Gulf RegionShenyang, China
| | - Yanbing Li
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang Agricultural UniversityShenyang, China
- Collaborative Innovation Center of Protected Vegetable Surround Bohai Gulf RegionShenyang, China
| | - Tianlai Li
- Key Laboratory of Protected Horticulture, Ministry of Education, Shenyang Agricultural UniversityShenyang, China
- Collaborative Innovation Center of Protected Vegetable Surround Bohai Gulf RegionShenyang, China
- *Correspondence: Tianlai Li,
| |
Collapse
|