Abstract:
Objectives This study evaluated the transcription levels of relative genes and physiological and chemical indices of foxtail millet genotypes under drought stress to understand the mechanism of drought resistance and screen germplasm for breeding.
Methods Seven foxtail millet genotypes were chosen to measure the contents of three osmotic regulation substances (proline, soluble sugar and malondialdehyde) and the activity of three antioxidant enzymes (superoxide dismutase peroxidase, and catalase) before and after drought treatment. We used the membership function analysis and cluster analysis method to evaluate their drought resistance comprehensively. The transcription sequencing method was used to detect the transcriptional level of differential genes to analyze the molecular mechanism of drought resistance in different cultivars.
Results Under drought stress, the contents of proline, soluble sugar and the activities of antioxidant enzymes in the shoots of ‘Henggu’, ‘280’ and ‘290’ rose significantly, while malondialdehyde content slightly increased. The relative expression level of transcription factors, antioxidant enzymes, and glutamine synthetase genes was (P<0.05) higher than other cultivars. However, the observed changes in all indices of cultivars ‘428’ and ‘718’ were opposite of ‘Henggu 13’, ‘280’ and ‘290’.
Conclusions Among the tested seven millet genotypes, ‘Henggu 13’, ‘280’, and ‘290’ showed stronger drought resistance, ‘239’ and ‘Yugu 18’ exhibited moderate drought resistance, and '428’ and '718’ were poorly resistant to drought. The different genotypes species activated the WRKY transcription factors and glutamine synthetase functional genes to express in varying degrees. Consequently, intracellular containers and antioxidant enzyme activities changed, resulting in different levels of drought resistance.
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