4.2 CRIR1 is a novel lncRNA regulating plant tolerance to cold stress
Plant lncRNAs are expected to play important roles in response to environmental conditions, and thousands of lncRNAs have been identified in various plant species (Li, Eichten, Shimizu, Petsch, Yeh, Wu, Chettoor, Givan, Cole, Fowler, Evans, Scanlon, Yu, Schnable, Timmermans, Springer & Muehlbauer, 2014, Wang, Chung, Liu, Jang, Kean, Xu & Chua, 2014, Xiao, Yuan, Guo, Hou, Yin, Zhang & Li, 2015, Xin, Wang, Yao, Song, Hu, Qin, Xie, Peng, Ni & Sun, 2011, Zhang, Han, Guo, Liu, Zheng, Wu & Jin, 2014). Besides, there has been a rapid increase in the number of well-studied lncRNAs involved in abiotic stresses response, such asSVALKA (Kindgren, Ard, Ivanov & Marquardt, 2018), DRIR(Qin et al., 2017), and Cis-NATZmNAC48 (Mao et al., 2021). However, for revealing the functions of plant lncRNA in cold stress response is still lagging because most plant lncRNAs are expressed at low levels and are not evolutionarily conserved across species. In the present study, an intergenic lncRNA, CRIR1 , was identified, whose expression was significantly induced by cold stress. Compared with WT, overexpression of CRIR1 in cassava could significantly accumulate high leve of proline, thus leading to enhanced survival rates under cold-treated conditions. The cellular morphological characteristics suggested that the expression ofCRIR1 can protect the cellular membrane systems from low temperatures. The discovery of CRIR1 provides a new avenue to explore a previously unknown aspect of plant cold stress response.