Ren Yi, Li Junpeng, Liu Jingjing, Zhang Zhen, Song Yue, Fan Dongying, Liu Minying, Zhang Lipeng, Xu Yuanyuan, Guo Dinghan, He Juan, Song Shiren, Gao Zhen, Ma Chao
Shanghai Collaborative Innovation Center of Agri-Seeds, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, China.
Plants (Basel). 2023 Jun 15;12(12):2332. doi: 10.3390/plants12122332.
Circular RNAs (circRNAs) serve as covalently closed single-stranded RNAs and have been proposed to influence plant development and stress resistance. Grapevine is one of the most economically valuable fruit crops cultivated worldwide and is threatened by various abiotic stresses. Herein, we reported that a circRNA () processed from the second exon of the pentatricopeptide repeat family gene was preferentially expressed in leaves and responded to salt and drought but not heat stress in grapevine. Additionally, the second exon sequence of was highly conserved, but the biogenesis of is species-dependent in plants. It was further found that the overexpressed can slightly decrease the abundance of the cognate host gene, and the neighboring genes are barely affected in the grapevine callus. Furthermore, we also successfully overexpressed the and found that the deteriorated the growth during heat, salt, and drought stresses in . However, the biological effects on grapevine callus were not always consistent with those of . Interestingly, we found that the transgenic plants of linear counterpart sequence also conferred the same phenotypes as those of circRNA during the three stress conditions, no matter what species it is. Those results imply that although the sequences are conserved, the biogenesis and functions of are species-dependent. Our results indicate that the plant circRNA function investigation should be conducted in homologous species, which supports a valuable reference for further plant circRNA studies.
环状RNA（circRNAs）是共价闭合的单链RNA，被认为会影响植物发育和抗逆性。葡萄是全球种植的最具经济价值的水果作物之一，受到各种非生物胁迫的威胁。在此，我们报道了一个由五肽重复序列家族基因第二个外显子加工而来的环状RNA（）在葡萄叶片中优先表达，并且对盐胁迫和干旱胁迫有响应，但对热胁迫无响应。此外，的第二个外显子序列高度保守，但其生物合成在植物中具有物种依赖性。进一步发现，过表达的会略微降低同源宿主基因的丰度，而葡萄愈伤组织中的邻近基因几乎不受影响。此外，我们还成功过表达了，发现其在热、盐和干旱胁迫下会使的生长恶化。然而，对葡萄愈伤组织的生物学效应并不总是与的一致。有趣的是，我们发现线性对应序列的转基因植物在这三种胁迫条件下也表现出与环状RNA相同的表型，无论其属于何种物种。这些结果表明，尽管序列保守，但其生物合成和功能具有物种依赖性。我们的结果表明，植物环状RNA功能研究应在同源物种中进行，这为进一步的植物环状RNA研究提供了有价值的参考。
