Transcriptome analysis of drought tolerance and utility assessment of DnaJ gene expression as a potential index for drought resistance evaluation in maize

• Published in: Euphytica 2022-09, Vol.218 (9), Article 136
• Main Authors: Dong, Anyi, Zenda, Tinashe, Liu, Xinyue, Wang, Yafei, Li, Jiao, Yang, Yatong, Liu, Songtao, Duan, Huijun
• Format: Article
• Language: English
• Subjects: Analysis; Biomedical and Life Sciences; Biotechnology; Cellular signal transduction; Cereal crops; Corn; Crop growth; Crops; Cultivars; Developmental stages; DnaJ gene; Drought; Drought resistance; Droughts; Evaluation; Gene expression; Genes; Genetic research; Kinases; Life Sciences; Plant breeding; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Protein kinase; Ribonucleic acid; RNA; Signal transduction; Transcriptomes
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-022-03088-8

Drought tolerance is a very complex trait, controlled by multiple genes, difficult to identify and evaluate in maize. Here, we employed RNA-seq transcriptome analysis to identify key differentially expressed genes (DEGs) responding to drought stress in maize at different crop growth stages. Resultantly, 666, 2417, and 7375 drought-responsive DEGS were detected at the flare, tasseling, and grain-filling stages, respectively. Among these, two candidate genes, DnaJ and a putative WAK family receptor-like protein kinase, involved in molecular chaperon activities and cell signal transduction, respectively, were found to be co-expressed across all three crop growth stages, and were suggested as the main contenders  underpinning drought tolerance in maize. Further, by way of qRT-PCR analysis, other drought resistance indices, 5-level-classification criterion and two sets of maize verification materials, we tested the utility of using DnaJ gene expression as a potential index for drought resistance evaluation in maize. We observed that DnaJ successfully classified the different materials into their expected drought resistance categories. Moreover, RNA-seq analysis and qRT-PCR analysis results were consistent to each other. These observations showed that DnaJ gene expression can accurately, consistently and conveniently be employed as a potential index for drought resistance evaluation of maize cultivars. Besides augmenting the commonly used indices for drought resistance evaluation, DnaJ gene expression method takes into account the crop developmental stages, physiological processes and the yield change dynamics, and therefore, is suggested as a much more simple, accurate, flexible, reliable and convenient alternative. This method can play a huge role in drought resistance screening of maize materials for breeding.