Mathew Iny Elizebeth, Priyadarshini Richa, Mahto Arunima, Jaiswal Priya, Parida Swarup K, Agarwal Pinky
National Institute of Plant Genome Research New Delhi India.
Plant Direct. 2020 Sep 4;4(9):e00249. doi: 10.1002/pld3.249. eCollection 2020 Sep.
NAC transcription factors (TFs) are known for their role in development and stress. This article attempts to functionally validate the role of rice / () during seed development. The gene is seed-specific and its promoter directs reporter expression in the developing endosperm and embryo in rice transgenic plants. Furthermore, rice transgenic plants ectopically expressing / have a plantlet lethal phenotype with hampered vegetative growth, but increased tillers and an altered shoot apical meristem structure. The vegetative cells of these plantlets are filled with distinct starch granules. RNAseq analysis of two independent plantlets reveals the differential expression of reproductive and photosynthetic genes. A comparison with seed development transcriptome indicates differential regulation of many seed-related genes by SS1/ ONAC025. Genes involved in starch biosynthesis, especially amylopectin and those encoding seed storage proteins, and regulating seed size are also differentially expressed. In conjunction, / shows highest expression in rice. As a TF, SS1/ ONAC025 is a transcriptional repressor localized to endoplasmic reticulum and nucleus. The article shows that / is a seed-specific gene promoting grain filling in rice, and negatively affecting vegetative growth.
NAC转录因子（TFs）以其在发育和胁迫中的作用而闻名。本文试图从功能上验证水稻/（）在种子发育过程中的作用。该基因是种子特异性的，其启动子在水稻转基因植物发育中的胚乳和胚中指导报告基因的表达。此外，异位表达/的水稻转基因植物具有植株致死表型，营养生长受阻，但分蘖增加且茎尖分生组织结构改变。这些植株的营养细胞充满了独特的淀粉颗粒。对两个独立植株的RNAseq分析揭示了生殖和光合基因的差异表达。与种子发育转录组的比较表明，SS1/ONAC025对许多种子相关基因有差异调控作用。参与淀粉生物合成的基因，尤其是支链淀粉以及编码种子贮藏蛋白和调节种子大小的基因也有差异表达。同时，/在水稻中表达最高。作为一种转录因子，SS1/ONAC025是一种定位于内质网和细胞核的转录抑制因子。本文表明，/是一个促进水稻籽粒充实并对营养生长产生负面影响的种子特异性基因。
