Gupta Asmita, Upadhyay Rakesh K, Prabhakar Rakhi, Tiwari Neerja, Garg Rashmi, Sane Vidhu A, Sane Aniruddha P
Plant Gene Expression Lab, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow 226001, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
Plant Gene Expression Lab, CSIR-National Botanical Research Institute (Council of Scientific and Industrial Research), Lucknow 226001, India; Sustainable Agricultural Systems Laboratory, USDA-ARS, Beltsville Agricultural Research Center, Beltsville, MD 20705-2350, USA; Deparment of Horticulture and Landscape Architecture, Purdue University, W. Lafayette, IN, USA.
Plant Sci. 2022 Jun;319:111249. doi: 10.1016/j.plantsci.2022.111249. Epub 2022 Mar 8.
SlDREB3 was identified as a ripening up-regulated gene of the AP2/ERF-domain family of transcription factors. Its manipulation affects processes primarily governed by ABA. It negatively regulates ABA responses in tomato by altering ABA levels/signaling and is, in turn, negatively regulated by ABA. SlDREB3 over-expression lines show higher transcript levels of the ABA metabolism genes CYP707A3 and UGT75C1 and an 85% reduction in ABA levels leading to early seed germination. In contrast, suppression lines show decreased CYP707A3/UGT75C1 expression, 3-fold higher ABA levels and delayed germination. The expression of other ABA signaling and response genes is also affected. Suppression of SlDREB3 accelerates the onset of ripening by 4-5 days while its over-expression delays it and also reduces final fruit size. SlDREB3 manipulation effects large scale changes in the fruit transcriptome with suppression lines showing early increase in ABA levels and activation of most ripening pathway genes that govern ethylene, carotenoids and softening. Strikingly, key transcription factors like CNR, NOR, RIN, FUL1, governing ethylene-dependent and ethylene-independent aspects of ripening, are activated early upon SlDREB3 suppression suggesting their control by ABA. The studies identify SlDREB3 as a negative regulator of ABA responses across tissues and a key ripening regulator controlling ethylene-dependent and ethylene-independent aspects.
SlDREB3被鉴定为转录因子AP2/ERF结构域家族的一个成熟上调基因。对其进行操控会影响主要由脱落酸（ABA）调控的过程。它通过改变ABA水平/信号传导来负向调控番茄中的ABA反应，反过来又受到ABA的负向调控。SlDREB3过表达系显示ABA代谢基因CYP707A3和UGT75C1的转录水平较高，ABA水平降低85%，导致种子提前萌发。相比之下，抑制系显示CYP707A3/UGT75C1表达降低，ABA水平高3倍，萌发延迟。其他ABA信号传导和反应基因的表达也受到影响。抑制SlDREB3可使成熟开始时间提前4 - 5天，而过表达则会延迟成熟并减小最终果实大小。操控SlDREB3会导致果实转录组发生大规模变化，抑制系显示ABA水平早期升高，以及大多数控制乙烯、类胡萝卜素和软化的成熟途径基因被激活。引人注目的是，像CNR、NOR、RIN、FUL1这样控制成熟的乙烯依赖性和乙烯非依赖性方面的关键转录因子，在SlDREB3被抑制后早期就被激活，这表明它们受ABA调控。这些研究将SlDREB3鉴定为跨组织ABA反应的负调节因子以及控制乙烯依赖性和乙烯非依赖性方面的关键成熟调节因子。
