Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Key Laboratory of Sugarcane Biology and Genetic Breeding, Ministry of Agriculture and Rural Affairs, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China; College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China; National Key Laboratory for Tropical Crop Breeding, Kaiyuan, 661699, Yunnan, China.
Plant Physiol Biochem. 2023 Jul;200:107760. doi: 10.1016/j.plaphy.2023.107760. Epub 2023 May 12.
Sugarcane is an important sugar and energy crop and smut disease caused by Sporisorium scitamineum is a major fungal disease which can seriously reduce the yield and quality of sugarcane. In plants, TGACG motif binding (TGA) transcription factors are involved in the regulation of salicylic acid (SA) and methyl jasmonate (MeJA) signaling pathways, as well as in response to various biotic and abiotic stresses. However, no TGA-related transcription factor has been reported in Saccharum. In the present study, 44 SsTGA genes were identified from Saccharum spontaneum, and were assorted into three clades (I, II, III). Cis-regulatory elements (CREs) analysis revealed that SsTGA genes may be involved in hormone and stress response. RNA-seq data and RT-qPCR analysis indicated that SsTGAs were constitutively expressed in different tissues and induced by S. scitamineum stress. In addition, a ScTGA1 gene (GenBank accession number ON416997) was cloned from the sugarcane cultivar ROC22, which was homologous to SsTGA1e in S. spontaneum and encoded a nucleus protein. It was constitutively expressed in sugarcane tissues and up-regulated by SA, MeJA and S. scitamineum stresses. Furthermore, transient overexpression of ScTGA1 in Nicotiana benthamiana could enhance its resistance to the infection of Ralstonia solanacearum and Fusarium solani var. coeruleum, by regulating the expression of immune genes related to hypersensitive response (HR), ethylene (ET), SA and jasmonic acid (JA) pathways. This study should contribute to our understanding on the evolution and function of the SsTGA gene family in Saccharum, and provide a basis for the functional identification of ScTGA1 under biotic stresses.
甘蔗是一种重要的糖料和能源作物，由盾孢霉引起的黑穗病是一种主要的真菌病害，可严重降低甘蔗的产量和品质。在植物中，TGACG 基序结合（TGA）转录因子参与水杨酸（SA）和茉莉酸甲酯（MeJA）信号通路的调节，以及对各种生物和非生物胁迫的响应。然而，在甘蔗中尚未报道与 TGA 相关的转录因子。本研究从甘蔗属野蕉中鉴定出 44 个 SsTGA 基因，并分为三个分支（I、II、III）。顺式调控元件（CREs）分析表明，SsTGA 基因可能参与激素和应激反应。RNA-seq 数据和 RT-qPCR 分析表明，SsTGAs 在不同组织中持续表达，并受盾孢霉胁迫诱导。此外，从甘蔗品种 ROC22 中克隆出一个 ScTGA1 基因（GenBank 登录号 ON416997），与野蕉中的 SsTGA1e 同源，编码核蛋白。它在甘蔗组织中持续表达，并被 SA、MeJA 和盾孢霉胁迫上调。此外，ScTGA1 在本氏烟中的瞬时过表达可以通过调节与过敏反应（HR）、乙烯（ET）、SA 和茉莉酸（JA）途径相关的免疫基因的表达，增强其对青枯菌和尖孢镰刀菌的抗性。本研究有助于我们理解甘蔗 SsTGA 基因家族的进化和功能，并为生物胁迫下 ScTGA1 的功能鉴定提供了基础。
