Kuya Noriyuki, Nishijima Ryo, Kitomi Yuka, Kawakatsu Taiji, Uga Yusaku
Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba, Japan.
Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Japan.
Front Plant Sci. 2023 Jun 9;14:1193042. doi: 10.3389/fpls.2023.1193042. eCollection 2023.
Root system architecture affects the efficient uptake of water and nutrients in plants. The root growth angle, which is a critical component in determining root system architecture, is affected by root gravitropism; however, the mechanism of root gravitropism in rice remains largely unknown. In this study, we conducted a time-course transcriptome analysis of rice roots under conditions of simulated microgravity using a three-dimensional clinostat and following gravistimulation to detect candidate genes associated with the gravitropic response. We found that () genes, which are involved in the regulation of auxin transport, were preferentially up-regulated during simulated microgravity conditions and rapidly down-regulated by gravistimulation. We also found that the transcription factor A2s (s) and s, showed the similar expression patterns with the s. A co-expression network analysis and an in silico motif search within the upstream regions of the co-expressed genes revealed possible transcriptional control of s by HSFs. Because HSFA2s are transcriptional activators, whereas HSFB2s are transcriptional repressors, the results suggest that the gene regulatory networks governed by HSFs modulate the gravitropic response through transcriptional control of s in rice roots.
根系结构影响植物对水分和养分的有效吸收。根生长角度是决定根系结构的关键组成部分，受根向重力性影响；然而，水稻根向重力性的机制在很大程度上仍不清楚。在本研究中，我们使用三维回转器在模拟微重力条件下对水稻根进行了时间进程转录组分析，并在重力刺激后检测与向重力性反应相关的候选基因。我们发现，参与生长素运输调控的（）基因在模拟微重力条件下优先上调，并在重力刺激下迅速下调。我们还发现转录因子A2s（s）和s，与s表现出相似的表达模式。共表达网络分析以及对共表达基因上游区域的计算机基序搜索揭示了HSFs对s可能的转录调控。由于HSFA2s是转录激活因子，而HSFB2s是转录抑制因子，结果表明由HSFs调控的基因调控网络通过对水稻根中s的转录控制来调节向重力性反应。
