A NAC transcription factor, NOR-like1, is a new positive regulator of tomato fruit ripening
A NAC transcription factor, NOR-like1, is a new positive regulator of tomato fruit ripening
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NAC 转录因子 NOR-like1 是番茄果实成熟的新正调节因子
DOI：
10.1038/s41438-018-0111-5
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发表时间：
2018-12-21
影响因子：
8.7
通讯作者：
Fu, Da-Qi
中科院分区：
文献类型：
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作者：
Gao, Ying;Wei, Wei;Fu, Da-Qi
成熟的模式水果番茄（Solanum lycopersicum）是由一个转录因子网络，包括NAC（NAM，ATAF 1/2，和CUC 2）结构域蛋白，如不成熟（NOR），SINAC 1，和SINAC 4控制，但很少有人知道NAC的目标或他们如何调节成熟。在这里，我们进行了一个系统的搜索水果表达NAC基因，并表明沉默NOR-like！（Solyc 07 g 063420）使用病毒诱导的基因沉默（VIGS）抑制成熟的特定方面。当NOR-like 1功能被CRISPR/Cas9灭活时，成熟开始延迟14天，果实显示出明显减少的乙烯产生，延迟软化和叶绿素损失，以及减少的番茄红素积累。RNA测序分析和基因启动子分析表明，参与乙烯生物合成（SIACS 2，SIACS 4），颜色形成（SIGgpps 2，SISGR 1）和细胞壁代谢（SIPG 2a，SIPL，SICEL 2和SIEXP 1）的基因是NOR样1的直接靶点。电泳迁移率变动分析（EMSA），染色质免疫沉淀定量PCR（ChIP-qPCR），和双荧光素酶报告基因分析（DLR）证实，NOR-like 1结合到这些基因的启动子在体外和体内，并激活其表达。我们的研究结果表明，NOR-like 1是一个新的番茄果实成熟的正调控因子，在转录调控网络中发挥重要作用。
Ripening of the model fruit tomato (Solanum lycopersicum) is controlled by a transcription factor network including NAC (NAM, ATAF1/2, and CUC2) domain proteins such as No-ripening (NOR), SINAC1, and SINAC4, but very little is known about the NAC targets or how they regulate ripening. Here, we conducted a systematic search of fruit-expressed NAC genes and showed that silencing NOR-like! (Solyc07g063420) using virus-induced gene silencing (VIGS) inhibited specific aspects of ripening. Ripening initiation was delayed by 14 days when NOR-like1 function was inactivated by CRISPR/Cas9 and fruits showed obviously reduced ethylene production, retarded softening and chlorophyll loss, and reduced lycopene accumulation. RNA-sequencing profiling and gene promoter analysis suggested that genes involved in ethylene biosynthesis (SIACS2, SIACS4), color formation (SIGgpps2, SISGR1), and cell wall metabolism (SIPG2a, SIPL, SICEL2, and SIEXP1) are direct targets of NOR-like1. Electrophoretic mobility shift assays (EMSA), chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR), and dual-luciferase reporter assay (DLR) confirmed that NOR-like1 bound to the promoters of these genes both in vitro and in vivo, and activated their expression. Our findings demonstrate that NOR-like1 is a new positive regulator of tomato fruit ripening, with an important role in the transcriptional regulatory network.