DREB/CBF expression in wheat and barley using the stress‐inducible promoters of HD‐Zip I genes: impact on plant development, stress tolerance and yield

Abstract

Summary Networks of transcription factors regulate diverse physiological processes in plants to ensure that plants respond to abiotic stresses rapidly and efficiently. In this study, expression of two DREB/CBF genes, TaDREB3 and TaCBF5L, was modulated in transgenic wheat and barley, by using stress‐responsive promoters HDZI‐3 and HDZI‐4. The promoters were derived from the durum wheat genes encoding the γ‐clade TFs of the HD‐Zip class I subfamily. The activities of tested promoters were induced by drought and cold in leaves of both transgenic species. Differences in sensitivity of promoters to drought strength were dependent on drought tolerance levels of cultivars used for generation of transgenic lines. Expression of the DREB/CBF genes under both promoters improved drought and frost tolerance of transgenic barley, and frost tolerance of transgenic wheat seedlings. Expression levels of the putative TaCBF5L downstream genes in leaves of transgenic wheat seedlings were up‐regulated under severe drought, and up‐ or down‐regulated under frost, compared to those of control seedlings. The application of TaCBF5L driven by the HDZI‐4 promoter led to the significant increase of the grain yield of transgenic wheat, compared to that of the control wild‐type plants, when severe drought was applied during flowering; although no yield improvements were observed when plants grew under well‐watered conditions or moderate drought. Our findings suggest that the studied HDZI promoters combined with the DREB/CBF factors could be used in transgenic cereal plants for improvement of abiotic stress tolerance, and the reduction of negative influence of transgenes on plant development and grain yields.

Transcriptome Analysis Reveals Potential Roles of Abscisic Acid and Polyphenols in Adaptation of Onobrychis viciifolia to Extreme Environmental Conditions in the Qinghai-Tibetan Plateau

“…Ectopic expression of StDREB2 of Solanum tuberosum in cotton ( Gossypium barbadense ) enhanced the drought resistance, while ectopic expression of ScDREB10 of Syntrichia caninervis in Arabidopsis increased osmotic and salt tolerance of transgenic plants. Furthermore, overexpression of TaDREB3 improved frost resistance of transgenic wheat seedlings [ 59 , 60 , 61 ]. In addition, DEAR4 which is a member of the DREB subfamily was reported to positively regulate the cell death and leaf senescence, and to be responsive to multiple stressors in A. thaliana [ 62 , 63 ].…”

Transcription Factors in Plant Stress Responses: Challenges and Potential for Sugarcane Improvement

“…TaDREB1 genes were induced as a result of DRE-binding protein (a transcript activator), thereby improving the tendency of wheat plants to tolerate the osmotic variations [154]. Transgenic wheat and barley carrying two DREB/CBF genes TaDREB3 and TaCBF5L under the stress-responsive promoters HDZI-3 and HDZI-4 showed enhanced tolerance towards frost in wheat and drought resistance in barley [155]. Expression of SodERF3 was induced by ABA, salt stress and wounding in sugarcane and overexpression of this gene in transgenic tobacco plants increased tolerance to drought and osmotic stresses [156] 5.3.…”

Genome-wide characterization and expression profiling of Eucalyptus grandis HD-Zip gene family in response to salt and temperature stress

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