Identification and characterization of tomato gibberellin 2-oxidases (GA2oxs) and effects of fruit-specific SlGA2ox1 overexpression on fruit and seed growth and development  

作　　者：Shen Chen Xiaojing Wang Liying Zhang Shanshan Lin Decai Liu Quanzhi Wang Shanya Cai Rania El-Tanbouly Lijun Gan Han Wu Yi Li 

机构地区：[1]State Key Laboratory of Crop Genetics and Germplasm Enhancement,College of Horticulture,Nanjing Agricultural University,Nanjing,210095,China [2]College of Life Sciences,Nanjing Agricultural University,Nanjing,210095,China [3]Jiangsu Polytechnic College of Agriculture and Forestry,Zhenjiang,212400,China [4]Jiangsu Engineering and Technology Center for Modern Horticulture,Zhenjiang,212400,China [5]Department of Plant Science and Landscape Architecture,University of Connecticut,Storrs,06269,CT,USA

出　　处：《Horticulture Research》2016年第1期12-20,共9页园艺研究（英文）

基　　金：The research was supported by the following:General Financial Grant from the China Postdoctoral Science Foundation(2015M581812);Special Financial Grant from the China Postdoctoral Science Foundation(2016T90471);A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).

摘　　要：Gibberellins(GAs)play a crucial role in growth and development of the tomato fruit.Previously published studies focusing on the effect of GAs on tomato fruits used chemical treatments,constitutive overexpression or silencing of GA biosynthetic and catabolic genes globally throughout the plant.Fruit-specific overexpression of GA catabolic enzyme genes GA2-oxidases(GA2oxs),however,may provide an alternative method to study the role of endogenous GAs on the fruit development.In this study,we have identified 11 SlGA2ox proteins in tomato that are classified into three subgroups.Motif analysis and multiple sequence alignments have demonstrated that all SlGA2oxs,except SlGA2ox10,have similar motif compositions and high-sequence conservation.Quantitative reverse transcription-PCR analysis has showed that SlGA2oxs exhibit differential expression patterns in tomato fruits at different developmental stages.When the fruit-specific promoter TFM7 was used to control the expression of SlGA2ox1,we observed no changes in growth and development of vegetative organs.However,fruit weight,seed number and germination rate were significantly affected.We also treated tomato fruits with GA biosynthesis inhibitor and observed phenotypes similar to those of the transgenic fruits.Furthermore,we have demonstrated that expression of cell expansion and GA responsive genes were downregulated in transgenic tomato fruits,supporting that overexpression of the SlGA2ox1 leads to reduction in endogenous GAs.This study provides additional evidence that endogenous GAs and the SlGA2ox1 gene play an important role in controlling on fruit weight,seed development and germination in tomato plant.

关 键 词：specific ENDOGENOUS FRUIT 

分 类 号：S64[农业科学—蔬菜学]