Ectopic expression of TaOEP16-2-5B , a wheat plastid outer envelope protein gene, enhances heat and drought stress tolerance in transgenic Arabidopsis plants

AbstractWith the changing climatic conditions, drought has become one of the most threatening abiotic stress factors that adversely affect rice cultivation and productivity. Although the involvement of the jacalin domain-containing protein, OsSalT, has been reported in drought and salinity tolerance, its functional mechanism still remains largely unexplored. In this study, expression of the OsSalT gene was found to be positively correlated with the drought tolerance potential with its higher transcript abundance in the tolerant indica rice cultivar, Vandana and lower abundance in the susceptible cultivar, MTU1010. Moreover, the ectopic expression of OsSalT in tobacco imparted drought stress tolerance in the transgenic lines. The transgenic lines exhibited significantly improved growth and higher osmolyte accumulation over the wild-type (WT) plants together with the induction in the OsSalT expression under drought stress. Fascinatingly, the yeast two-hybrid and bimolecular fluorescence complementation (BiFC) analyses confirmed the interaction of OsSalT protein with two interesting transcription factors (TFs), OsNAC1 and OsDREB2A. In silico analysis further revealed that the OsSalT protein interacted with the regulatory domain of OsDREB2A and the C-terminal domain of OsNAC1 leading to their activation and induction of their downstream drought-responsive genes. Together, this study unravels a novel model for OsSalT-mediated regulation of drought tolerance in plants.

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Expression of maize heat shock transcription factor gene ZmHsf06 enhances the thermotolerance and drought-stress tolerance of transgenic Arabidopsis

Functional Plant Biology ◽

10.1071/fp15080 ◽

2015 ◽

Vol 42 (11) ◽

pp. 1080 ◽

Cited By ~ 16

Author(s):

Hui-cong Li ◽

Hua-ning Zhang ◽

Guo-liang Li ◽

Zi-hui Liu ◽

Yan-min Zhang ◽

...

Keyword(s):

Transcription Factor ◽

Drought Stress ◽

Heat Shock ◽

Stress Tolerance ◽

Transgenic Arabidopsis ◽

Germination Rate ◽

Heat Shock Transcription Factor ◽

Drought Stress Tolerance ◽

Acquired Thermotolerance ◽

A Genome

Based on the information of 25 heat shock transcription factor (Hsf) homologues in maize according to a genome-wide analysis, ZmHsf06 was cloned from maize leaves and transformed into Arabidopsis thaliana (L. Heynh.) (ecotype, Col-0). Three transgenic positive lines were selected to assess the basic and acquired thermotolerance and drought-stress tolerance under stresses and for some physiological assays. The sequence analysis indicates that ZmHsf06 contained the characteristic domains of class A type plant Hsfs. The results of qRT–PCR showed that the expression levels of ZmHsf06 were elevated by heat shock and drought stress to different extents in three transgenic lines. Phenotypic observation shows that compared with the Wt (wild-type) controls, the overexpressing ZmHsf06 of Arabidopsis plants have enhanced basal and acquired thermotolerance, stronger drought-stress tolerance and growth advantages under mild heat stress conditions. These results are further confirmed by physiological and biochemical evidence that transgenic Arabidopsis plants exhibit higher seed germination rate, longer axial-root length, higher activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), higher leaf chlorophyll content, but lower relative electrical conductivity (REC), malondialdehyde (MDA) and osmotic potential (OP) than the Wt controls after heat shock and drought treatments. ZmHsf06 may be a central representative of maize Hsfs and could be useful in molecular breeding of maize or other crops for enhanced tolerances, particularly during terminal heat and drought stresses.

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