School of Life Sciences, Southwest University, Chongqing, China.
School of Life Sciences, Southwest University, Chongqing, China.
Plant Physiol Biochem. 2023 Dec;205:108202. doi: 10.1016/j.plaphy.2023.108202. Epub 2023 Nov 20.
RNA helicases (RHs) are required for most aspects of RNA metabolism and play an important role in plant stress tolerance. Heat stress (HS) causes the deleterious effects on plant cells, such as membrane disruption and protein misfolding, which results in the inhibition of plant growth and development. In this study, CaRH57 was identified from pepper (Capsicum annuum) and encodes a DEAD-box RH. CaRH57 was induced by HS, and overexpression of CaRH57 in Atrh57-1 rescued the glucose-sensitive phenotype of Atrh57-1, suggesting the functional replacement of CaRH57 to AtRH57. The nucleolus-localized CaRH57 possessed a RH activity in vitro. CaRH57 knockdown impaired pepper heat tolerance, showing severe necrosis and enhanced ROS accumulation in the region of the shoot tip. Additionally, accumulation of aberrant-spliced CaHSFA1d and CaHSFA9d was enhanced, and the corresponding mature mRNA levels were reduced in the TRV2 (Tobacco rattle virus)-CaRH57-infected plants compared with the control plants under HS. Overall, these results suggested that CaRH57 acted as a RH to confer pepper heat tolerance and was required for the proper pre-mRNA splicing of some HS-related genes.
RNA 解旋酶（RHs）是大多数 RNA 代谢过程所必需的，在植物应激耐受中发挥着重要作用。热应激（HS）对植物细胞造成有害影响，如膜破裂和蛋白质错误折叠，从而抑制植物的生长和发育。在本研究中，从辣椒（Capsicum annuum）中鉴定出 CaRH57，并对其进行了编码。CaRH57 被 HS 诱导，过表达 CaRH57 在 Atrh57-1 中挽救了 Atrh57-1 的葡萄糖敏感表型，表明 CaRH57 对 AtRH57 的功能替代。核仁定位的 CaRH57 在体外具有 RH 活性。CaRH57 的敲低削弱了辣椒的耐热性，导致在茎尖区域出现严重坏死和 ROS 积累增加。此外，异常剪接的 CaHSFA1d 和 CaHSFA9d 的积累增强，而在 HS 下，TRV2（烟草脆裂病毒）-CaRH57 感染植物中的相应成熟 mRNA 水平与对照植物相比降低。总的来说，这些结果表明 CaRH57 作为一种 RH 赋予了辣椒耐热性，并需要正确的前体 mRNA 剪接一些与 HS 相关的基因。
