Overexpression of a tomato miR171 target gene SlGRAS24 impacts multiple agronomical traits via regulating gibberellin and auxin homeostasis
Overexpression of a tomato miR171 target gene SlGRAS24 impacts multiple agronomical traits via regulating gibberellin and auxin homeostasis
复制标题
番茄 miR171 靶基因 SlGRAS24 的过度表达通过调节赤霉素和生长素稳态影响多种农艺性状
DOI：
10.1111/pbi.12646
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发表时间：
2017-04-01
影响因子：
13.8
通讯作者：
Li, Zhengguo
中科院分区：
文献类型：
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作者：
Huang, Wei;Peng, Shiyuan;Li, Zhengguo
在拟南芥中，miR 171-GRAS模块已被阐明为分生组织维持的关键参与者。然而，关于其在水果作物如番茄（Solanum lycopersicum）中的作用的知识仍然很少。我们先前鉴定番茄SlGRAS 24为Sly-miR 171的靶基因。为了研究这种可能的转录因子的作用，我们产生了在SlGRAS 24启动子（proSlGRAS 24-GUS）下低表达SlGRAS 24、过表达SlGRAS 24、过表达Sly-miR 171和表达β-葡萄糖醛酸酶（GUS）的转基因番茄植物。过表达SlGRAS 24（SlGRAS 24-OE）的植物具有与多个农艺性状相关的多效性表型，所述农艺性状包括植物高度、开花时间、叶结构、侧枝分支数量、根长度、座果和发育。结果表明，在S1 GRAS 24-OE幼苗中，许多GA/生长素相关基因表达下调，对外源IAA/NAA或GA_3的反应性发生改变。此外，还观察到SlGRAS 24 - 0 E中受损的坐果和发育。这些新鉴定的番茄中的SlGRAS 24同源物的表型后来被证明是由受损的花粉囊和较少的有活力的花粉粒引起的。在开花期，比较转录组的结果表明，改变了参与花粉发育和激素信号的基因的表达。综上所述，我们的数据表明，SlGRAS 24通过调节赤霉素和生长素信号传导参与一系列发育过程，这为番茄发育中激素串扰的参与提供了新的线索。
In Arabidopsis, the miR171-GRAS module has been clarified as key player in meristem maintenance. However, the knowledge about its role in fruit crops like tomato (Solanum lycopersicum) remains scarce. We previously identified tomato SlGRAS24 as a target gene of Sly-miR171. To study the role of this probable transcription factor, we generated transgenic tomato plants underexpressing SlGRAS24, overexpressing SlGRAS24, overexpressing Sly-miR171 and expressing b-glucuronidase (GUS) under the SlGRAS24 promoter (proSlGRAS24-GUS). Plants overexpressing SlGRAS24 (SlGRAS24-OE) had pleiotropic phenotypes associated with multiple agronomical traits including plant height, flowering time, leaf architecture, lateral branch number, root length, fruit set and development. Many GA/auxin-related genes were down-regulated and altered responsiveness to exogenous IAA/NAA or GA3 application was observed in SlGRAS24-OE seedlings. Moreover, compromised fruit set and development in SlGRAS24-OE was also observed. These newly identified phenotypes for SlGRAS24 homologs in tomato were later proved to be caused by impaired pollen sacs and fewer viable pollen grains. At anthesis, the comparative transcriptome results showed altered expression of genes involved in pollen development and hormone signalling. Taken together, our data demonstrate that SlGRAS24 participates in a series of developmental processes through modulating gibberellin and auxin signalling, which sheds new light on the involvement of hormone crosstalk in tomato development.