State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China.
Jiangsu Key Laboratory for the Research and Utilization of Plant Resources, Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210014, China.
Genomics. 2020 Nov;112(6):4348-4360. doi: 10.1016/j.ygeno.2020.07.029. Epub 2020 Jul 24.
Extensins (EXTs) are major protein components in plant cell walls that play crucial roles in higher plants. The function of EXTs has been reported in several plants but is limited in tomato, especially in fruit ripening. In this study, we identified 83 EXTs in tomato, and divided them into seven groups. The gene intron-exon structure and protein-motif composition of SlEXTs were similar within each group but different among groups. SlEXT genes showed different expression patterns in roots, leaves, flowers and fruits, and some SlEXT gene expressions in flowers could be regulated by treatments of auxin, gibberellic acid and jasmonic acid. In particular, SlSEXT8 had higher and increased expression during tomato fruit ripening, and its expression could be induced by ethylene, suggesting SlSEXT8 may be involved in tomato fruit softening. The result provides insights into the function of EXTs, and will facilitate to further study EXT roles in tomato fruit ripening.
伸展蛋白（EXTs）是植物细胞壁的主要蛋白成分，在高等植物中发挥着关键作用。在几种植物中已经报道了 EXT 的功能，但在番茄中，特别是在果实成熟过程中，其功能是有限的。在这项研究中，我们在番茄中鉴定了 83 种 EXT，并将它们分为 7 组。SlEXTs 的基因内含子-外显子结构和蛋白基序组成在每个组内相似，但在组间不同。SlEXT 基因在根、叶、花和果实中的表达模式不同，一些 SlEXT 基因在花中的表达可以被生长素、赤霉素和茉莉酸处理所调控。特别是，SlSEXT8 在番茄果实成熟过程中表达量较高且不断增加，其表达可以被乙烯诱导，表明 SlSEXT8 可能参与了番茄果实软化。该结果为 EXT 的功能提供了新的见解，并将有助于进一步研究 EXT 在番茄果实成熟过程中的作用。
