Functional analysis ofTaDi19A, a salt-responsive gene in wheat

Abstract

A salinity stress upregulated expressed sequence tag (EST) was selected from a suppression subtractive hybridization cDNA library, constructed from the salinity-tolerant wheat cultivar Shanrong No. 3. Sequence analysis showed that the corresponding gene (named TaDi19A) belonged to the Di19 family. TaDi19A was constitutively expressed in both the root and leaf of wheat seedlings grown under nonstressed conditions, but was substantially up-regulated by the imposition of stress (salinity, osmotic stress and cold), or the supply of stress-related hormones [abscisic acid (ABA) and ethylene]. The heterologous over-expression of TaDi19A in Arabidopsis thaliana increased the plants' sensitivity to salinity stress, ABA and mannitol during the germination stage. Root elongation in these transgenic lines showed a reduced tolerance to salinity stress and a reduced sensitivity to ethophon. The expression of the ABA signal pathway genes ABI1, RAB18, ERD15 and ABF3, and SOS2 (SOS pathway) was altered in the transgenic lines. TaDi19A plays a role in the plant's response to abiotic stress, and some possible mechanisms of its action are proposed.

Two cotton Cys2/His2-type zinc-finger proteins, GhDi19-1 and GhDi19-2, are involved in plant response to salt/drought stress and abscisic acid signaling

“…Recently, a study indicated that TaDi19A is up-regulated in wheat seedlings by abiotic stresses (such as salinity, osmotic stress and cold) and stress-related hormones (such as ABA and ethylene). Overexpression of TaDi19A in Arabidopsis increases the sensitivity of transgenic plants to NaCl, mannitol and ABA during seed germination (Li et al 2010). However, GhDi19-1/-2 transgenic plants responded to mannitol in a same manner as wild type, although both Di19 genes were induced by drought stress in cotton.…”

“…Interestingly, AtDi19-7 has been implicated in regulating light signaling and responses, but its expression is not changed in response to abiotic stress treatments (Kang et al 2005), suggesting that AtDi19 proteins may functionally participate in different signaling pathways. A more recent study revealed that wheat Di19A may play a role in plant responding to abiotic stress (Li et al 2010). Besides, previous studies showed that some of the other zinc-finger proteins are involved in abiotic stress signaling in Arabidopsis.…”

Functional Diversity of Early Responsive to Dehydration (ERD) Genes in Soybean

“…These plants showed an increase in the number of ERD15 transcripts relative to control plants [44]. Transgenic wheat plants over-expressing TaDi19A, a gene responsive to salinity in wheat, exhibited increased expression of ERD15 [45]. In contrast to these findings, Arabidopsis plants over-expressing ERD15 demonstrated susceptibility to drought and freezing [35].…”

A Novel Gene SbSI-2 Encoding Nuclear Protein from a Halophyte Confers Abiotic Stress Tolerance in E. coli and Tobacco

“…Nuclear localization is an integral part of abiotic stress response. Many stress-associated proteins, like some TFs (bZIP, DREB, MYC/MYB, NAC, C 2 H 2 zinc finger protein Msn2P), some kinase gene and a number of functional proteins belong to a subset of cellular proteins that localize to the nucleus [11], [12], [53], [54], [55], [56], [57], [58], [59]. Genomic organization study showed that SbSI-2 is an intronless gene (Fig.…”