Abstract：
The NAC (NAM, ATAF, and CUC) is one of the largest transcription factor gene families in plants. In this study, 180, 141, and 131 NAC family members were identified from Saccharum complex, including S. officinarum, S. spontaneum, and Erianthus rufipilus. The Ka/Ks ratio of ATAF subfamily was all less than 1. Besides, 52 ATAF members from 12 representative plants were divided into three clades and there was only a significant expansion in maize. Surprisingly, ABA and JA cis-elements were abundant in hormonal response factor, followed by transcriptional regulator and abiotic stressor. The ATAF subfamily was differentially expressed in various tissues, under low temperature and smut pathogen treatments. Further, the ScATAF1 gene, with high expression in leaves, stem epidermis, and buds, was isolated. The encoded protein, lack of self-activation activity, was situated in the cell nucleus. Moreover, SA and JA stresses down-regulated the expression of this gene, while ABA, NaCl, and 4°C treatments led to its up-regulation. Interestingly, its expression in the smut susceptible sugarcane cultivars was much higher than the smut resistant ones. Notably, the colors presented slight brown in tobacco transiently overexpressing ScATAF1 at 1 d after DAB staining, while the symptoms were more obvious at 3 d after inoculation with Ralstonia solanacearum, with ROS, JA, and SA signaling pathway genes significantly up-regulated. We thus speculated ScATAF1 gene could negatively mediate hypersensitive reactions and produce ROS by JA and SA signaling pathways. These findings lay the groundwork for in-depth investigation on the biological roles of ATAF subfamily in sugarcane.
摘要：
NAC（NAM，ATAF,而CUC)是植物中最年夜的转录因子基因家族之一。在这项研究中,从糖精复合体中鉴定出180、141和131个NAC家族成员，包括S.officinarum,S、自发性，和Erianthusrufipilus。ATAF亚家族的Ka/Ks比值均小于1。此外,将来自12个代表性植物的52个ATAF成员分成三个分支,并且在玉米中仅有显著的扩展。令人惊讶的是,ABA和JA顺式元素在激素反应因子中含量丰富，其次是转录调节因子和非生物应激源。ATAF亚家族在各种组织中差异表达,在低温和黑穗病病原体处理下。Further,ScATAF1基因，在叶子中高表达，茎表皮，和芽，被隔离。编码的蛋白质，缺乏自我激活活动，位于细胞核中。此外，SA和JA胁迫下调了该基因的表达，而ABA,NaCl,和4°C处理导致其上调。有趣的是,其在黑穗病易感甘蔗品种中的表达远高于抗黑穗病品种。值得注意的是,在DAB染色后1d短暂过表达ScATAF1的烟草中，颜色呈现浅褐色，而在接种青枯菌后3d症状更明显，ROS,JA,和SA信号通路基因显著上调。因此，我们推测ScATAF1基因可以负介导超敏反应，并通过JA和SA信号通路产生ROS。这些发现为深入研究甘蔗中ATAF亚家族的生物学作用奠定了基础。
