The multiple stress‐responsive transcription factor SlNAC1 improves the chilling tolerance of tomato

Abstract

NAC (NAM-ATAF1, 2-CUC2) family members play important roles in various environmental responses. Here, we cloned a full-length NAC gene (954 bp) from Solanum lycopersicum (SlNAC1). This gene belonged to ATAF subfamily which included ATAF1 and ATAF2 of Arabidopsis thaliana. SlNAC1 expression was induced by chilling stress (4°C), heat stress (40°C), high salinity, osmotic stress and mechanical wounding. SlNAC1 transcripts were enhanced after application of abscisic acid, methyl jasmonate, salicylic acid, gibberellin, ethylene, methyl viologen and hydrogen peroxide. The seedlings of transgenic plants overexpressing SlNAC1 grew more leaves but were shorter than wild-type (WT) plants. SlNAC1 overexpression increased the chilling tolerance of tomato plants by maintaining the higher maximal photochemical efficiency of photosystem II and oxygen-evolving activities. Compared with WT plants, transgenic plants showed higher superoxide dismutase (EC 1.15.1.1) and catalase (EC 1.11.1.6) activities, which reduced levels of H2 O2 and superoxide anion radicals and promoted lower ion leakage and malondialdehyde content. The expression level of SlCBF1 in transgenic plants was also higher than that in WT plants under both normal conditions and chilling stress; this increased expression may be the main factor influencing the high chilling tolerance of transgenic plants. The results suggest that SlNAC1 plays important roles in diversiform plant-stress responses and diverse signaling pathways.

Overexpression of two ATNAC3-related genes improves drought and salt tolerance in tomato (Solanum lycopersicum L.)

“…2a, b, the induction patterns of NAC genes belonging to the ATAF1 subfamily varied in response to stress treatments where Solyc11g017470 had the highest expression levels after drought and salinity stress followed by Solyc04g009440 (SlNAC1). This was in general agreement with previous results where Solyc04g009440 (SlNAC1) showed strong induction in response to different abiotic stresses that included drought and salinity (Yang et al 2011;Ma et al 2013;Su et al 2014). Similarly, the NAP subfamily members, Solyc04g005610 and Solyc05g007770 (SlNAC2), and the ATNAC3 subfamily, Solyc07g063410 and Solyc12g013620, were found to be responsive to the drought and salinity treatments (Fig.…”

“…The drought tolerance behavior of SlNAC3 genes was similar to their counterparts in Arabidopsis where the overexpression of ANAC019, ANAC055 and ANAC072 conferred drought tolerance (Tran et al 2004). Recently, the overexpression Solyc04g009440 (SlNAC1) in tomato plants enhanced chilling tolerance through the maintenance of higher oxygen-evolving enzymatic activities that lowered ion leakage and malondialdehyde content in stressed transgenic plants when compared with non-transgenic plants (Ma et al 2013). These results confirm that the bioinformatics approach used in this study was successful in predicting the functions of stress-related NAC genes in In conclusion, 12 stress related NAC genes were identified in tomato using different bioinformatics and molecular approaches.…”

“…In another study, the Solyc04g009440 (SlNAC1) gene was found to be induced by the Tomato Leaf Curl Virus and it was implicated in viral DNA replication (Selth et al 2005). Moreover, Solyc04g009440 (SlNAC1) was speculated to have important roles in mediating cross-talk between different stresses and hormonal signaling (Ma et al 2013). The second stress NAC subfamily, ATNAC3, included two NACs that showed similarity to ANAC055 and ANAC072 (also known as RD26 for Responsive to Desiccation 26) genes, which are induced by salt and drought stresses and confer drought tolerance in Arabidopsis (Tran et al 2004) and tomato (Su et al 2014).…”

The overexpression of an Amaranthus hypochondriacus NF-YC gene modifies growth and confers water deficit stress resistance in Arabidopsis

“…A role for certain TFs, and more specifically for XERICO, a RING-H2 zinc finger factor that regulates drought tolerance and ABA biosynthesis in Arabidopsis [66], was implied by its induction in water stressed and recovered plants only. The abundance of NAC TF genes whose expression was modified in response to water deprivation, was also in accordance with this proposal, considering their role in signal crosstalk regulation between ABA and other phytohormones during stress adaptation [67]. In particular, the induction of VNI2 in recovered AhNF-YC OE Arabidopsis plants suggested the need for an ABA-related repression of xylem vessel formation and the activation of leaf aging and plant senescence programs during water stress and recovery [68].…”

Brassinosteroid alleviates chilling-induced oxidative stress in pepper by enhancing antioxidation systems and maintenance of photosystem II

“…Histochemical staining and quantitative determination of H 2 O 2 and O 2 2 Stained images of detached leaves specimens were obtained with 3,3-diaminobenzidine (DAB) and nitroblue tetrazolium (NBT) as described by Ma et al (2013).…”