Abstract:

To identify the role of hydroxyphenylpyruvate reductase (HPPR) in wheat stress, this study used homologous cloning to obtain a wheat HPPR gene which named TaHPPR. At the same time, the expressions of HPPR gene in tissues and under stress were analyzed. ‘Taiyuan 806’, ‘Xiaobaimai’, ‘Jingdong 8’ and ‘Jing 411’ were used as materials. We performed RT-qPCR analysis to determine TaHPPR gene expression levels in tissue and under stress. Sequence analysis showed that the TaHPPR gene contained a complete open reading frame of 975 bp, and encoded 324 amino acids. TaHPPR protein contained a NAD-binding domain structure. In addition, phylogenetic analysis indicated that TaHPPR gene was in the same branch of Triticum dicoccoides and their genetic relationships were extremely familiar. Expression profiling revealed that TaHPPR expressed in roots, spikelets (excluding stamens), and leaf sheaths, of which the expression level in roots was the highest. The expression of TaHPPR gene decreased under cold, drought, high salt and ABA stress treatment, In the high-salt resistance variety ‘Jingdong 8’, TaHPPR gene expression increased, while it was suppressed in the sensitive variety ‘Xiaobaimai’ and the moderate sensitive variety ‘Jing411’. The results of subcellular localization show that TaHPPR protein is mainly expressed in mitochondria, and the overexpression of TaHPPR gene may increase the salt tolerance in wheat. This study clarifies the expression characteristics of TaHPPR under adversity stress response and salt stress treatment in different varieties, and provides new gene resources and new ideas for studying the molecular mechanism of wheat resistance breeding.

Key words: wheat, hydroxyphenylpyruvate reductase, abiotic stress, salt resistance, subcellular localization