Saidi Mohamed Najib, Mergby Dhawya, Souibgui Amel, Yacoubi Ines
Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, P.O. Box 1177, Road Sidi Mansour 6 Km, Sfax, 3018, Tunisia.
Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax, P.O. Box 1177, Road Sidi Mansour 6 Km, Sfax, 3018, Tunisia.
Plant Physiol Biochem. 2022 Dec 1;192:1-9. doi: 10.1016/j.plaphy.2022.09.027. Epub 2022 Sep 30.
Plant-specific NAC transcription factors play important roles in plant development processes, hormone signaling and response to biotic and abiotic stresses. Here, a newly identified membrane-bound NAC gene, designated as TtNTL3A, was isolated from durum wheat. TtNTL3A was homologous to bread wheat TaNAC8 and rice OsNAC8. Moreover, yeast trans-activation assays revealed that TtNTL3A is a transcriptional activator. TtNTL3A was highly expressed in developing seeds and was induced by abiotic stresses, abscisic acid treatment and the infection with Fusarium graminearum. Besides, Transgenic Arabidopsis overexpressing TtNTL3A showed early flowering phenotype and higher tolerance to salt and drought stresses. RT-qPCR analysis revealed that drought and salt-responsive genes were highly expressed in transgenic lines compared to WT plants. Besides, these lines showed resistance to Fusarium graminearum, which was accompanied by a higher expression of pathogenesis-related genes (AtPR-1, Atpdf1.2, and AtNPR1) in TtNTL3A-OE lines. These findings suggest that TtNTL3A is an interesting target of genetic engineering to improve wheat tolerance to biotic and abiotic stresses.
植物特有的NAC转录因子在植物发育过程、激素信号传导以及对生物和非生物胁迫的响应中发挥着重要作用。在此，从硬粒小麦中分离出一个新鉴定的膜结合NAC基因，命名为TtNTL3A。TtNTL3A与面包小麦TaNAC8和水稻OsNAC8同源。此外，酵母反式激活分析表明TtNTL3A是一种转录激活因子。TtNTL3A在发育中的种子中高度表达，并受到非生物胁迫、脱落酸处理和禾谷镰刀菌感染的诱导。此外，过表达TtNTL3A的转基因拟南芥表现出早花表型以及对盐和干旱胁迫的更高耐受性。RT-qPCR分析表明，与野生型植物相比，干旱和盐响应基因在转基因株系中高度表达。此外，这些株系对禾谷镰刀菌具有抗性，这伴随着TtNTL3A过表达株系中病程相关基因（AtPR-1、Atpdf1.2和AtNPR1）的更高表达。这些发现表明，TtNTL3A是通过基因工程提高小麦对生物和非生物胁迫耐受性的一个有意义的靶点。
