Borràs Dionis, Barchi Lorenzo, Schulz Karina, Moglia Andrea, Acquadro Alberto, Kamranfar Iman, Balazadeh Salma, Lanteri Sergio
Department of Agricultural, Forest and Food Sciences, Plant Genetics and Breeding, University of Torino, Turin, Italy.
Max Planck Institute of Molecular Plant Physiology, Potsdam, Germany.
Front Genet. 2021 Oct 22;12:743902. doi: 10.3389/fgene.2021.743902. eCollection 2021.
L. is one of the most cultivated Solanaceae species, and in the open field, water limitation leading to drought stress affects its fruit quality, fruit setting, fruit size and ultimately yield. We identified stage-specific and a common core set of differentially expressed genes, following RNA-seq transcriptome analyses of a breeding line subjected to acute drought stress followed by recovery (rewatering), at three stages of plant development. Among them, two NAC transcription factor (TF) genes, i.e., CaNAC072 and CaNAC104, were always upregulated after drought stress and downregulated after recovery. The two TF proteins were observed to be localized in the nucleus following their transient expression in leaves. The expression of the two NACs was also induced by NaCl, polyethylene glycol (PEG) and abscisic acid (ABA) treatments, suggesting that is an early, while is a late abiotic stress-responsive gene. Virus-induced gene silencing (VIGS) of did not affect the pepper plantlet's tolerance to drought stress, while VIGS of increased drought tolerance. Heterologous expression of in as well as in plants mutated for its homolog did not increase drought stress tolerance. This highlights a different role of the two NAC homologs in the two species. Here, we discuss the complex role of NACs as transcriptional switches in the response to drought stress in bell pepper.
番茄是最常种植的茄科物种之一，在露天环境中，水分限制导致的干旱胁迫会影响其果实品质、坐果率、果实大小并最终影响产量。我们通过对一个育种系在植物发育的三个阶段进行急性干旱胁迫后再恢复（重新浇水）的RNA测序转录组分析，鉴定出了阶段特异性和一组共同的差异表达基因核心集。其中，两个NAC转录因子（TF）基因，即CaNAC072和CaNAC104，在干旱胁迫后总是上调，恢复后下调。在叶片中瞬时表达后，观察到这两种TF蛋白定位于细胞核中。这两个NAC基因的表达也受到NaCl、聚乙二醇（PEG）和脱落酸（ABA）处理的诱导，表明CaNAC072是早期而非CaNAC104是晚期非生物胁迫响应基因。CaNAC072的病毒诱导基因沉默（VIGS）不影响辣椒幼苗对干旱胁迫的耐受性，而CaNAC104的VIGS则提高了耐旱性。CaNAC104在拟南芥以及其同源基因发生突变的植物中的异源表达并未增加干旱胁迫耐受性。这突出了这两个NAC同源基因在这两个物种中的不同作用。在此，我们讨论了NACs作为转录开关在甜椒干旱胁迫响应中的复杂作用。
