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Title: Tomato locule number and fruit size controlled by natural alleles of lc and fas
Abstract

Improving yield by increasing the size of produce is an important selection criterion during the domestication of fruit and vegetable crops. Genes controlling meristem organization and organ formation work in concert to regulate the size of reproductive organs. In tomato,lcandfascontrol locule number, which often leads to enlarged fruits compared to the wild progenitors.LCis encoded by the tomato ortholog ofWUSCHEL(WUS), whereasFASis encoded by the tomato ortholog ofCLAVATA3 (CLV3). The critical role of theWUSCLV3 feedback loop in meristem organization has been demonstrated in several plant species. We show that mutant alleles for both loci in tomato led to an expansion of theSlWUSexpression domain in young floral buds 2–3 days after initiation. Single and double mutant alleles oflcandfasmaintain higherSlWUSexpression during the development of the carpel primordia in the floral bud. This augmentation and altered spatial expression ofSlWUSprovided a mechanistic basis for the formation of multilocular and large fruits. Our results indicated thatlcandfasare gain‐of‐function and partially loss‐of‐function alleles, respectively, while both mutations positively affect the size of tomato floral meristems. In addition, expression profiling showed thatlcandfasaffected the expression of several genes in biological processes including those involved in meristem/flower development, patterning, microtubule binding activity, and sterol biosynthesis. Several differentially expressed genes co‐expressed withSlWUShave been identified, and they are enriched for functions in meristem regulation. Our results provide new insights into the transcriptional regulation of genes that modulate meristem maintenance and floral organ determinacy in tomato.

 
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NSF-PAR ID:
10197221
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Plant Direct
Volume:
3
Issue:
7
ISSN:
2475-4455
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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