Molecular characterization and function analysis of the rice OsDUF1664 family

The functions of a large number of genes, including gene families with domains of unknown functions (DUF), still remain unclear. In this study, we analyzed four members of OsDUF1664 (OsDUF1664.1-OsDUF1664.4) in rice Nipponbare. By phylogenetic analysis, DUF1664 members in rice and Arabidopsis were classified into three major groups (I, II, III). Under drought conditions, the expression level of OsDUF1664.3 in rice was significantly elevated. Overexpression of OsDUF1664.3 in Escherichia coli led to a significant enhancement of catalase (CAT) and peroxidase (POD) activities, and improved bacterial resistance to drought. The results of this study will provide important information for further study of the function of the OsDUF1664 family in rice

Molecular characterization and function analysis of the rice OsDUF617 family

With the advance of sequencing technology, the number of sequenced genomes has been rapidly increasing. However, the functions of a large number of genes, including gene families with domains of unknown functions (DUF), still remain unclear. In this study, we analysed eight members of OsDUF617 (OsDUF617.1-OsDUF617.8) in rice Nipponbare. By phylogenetic analysis, all these OsDUF617 proteins could be classified into three major groups (I, II, III). We used real-time polymerase chain reaction to examine the expression of all these OsDUF617 members in 15 distinct rice tissues. The expression of these members under various abiotic stress and abscisic acid (ABA) conditions was also examined. Under drought conditions, the expression level of OsDUF617.8 in rice was significantly elevated. Overexpression of OsDUF617.8 in Escherichia coli led to a significant enhancement of catalase (CAT) and peroxidase (POD) activities, and improved bacterial resistance to osmotic stress. The results of this study will provide important information for further study of the function of the OsDUF617 family in rice. Supplemental data for this article is available online at 10.1080/13102818.2021.1934541

<i>OsWRKY97,</i> an Abiotic Stress-Induced Gene of Rice, Plays a Key Role in Drought Tolerance

Drought stress is one of the major causes of crop losses. The WRKY families play important roles in the regulation of many plant processes, including drought stress response. However, the function of individual WRKY genes in plants is still under investigation. Here, we identified a new member of the WRKY families, OsWRKY97, and analyzed its role in stress resistance by using a series of transgenic plant lines. OsWRKY97 positively regulates drought tolerance in rice. OsWRKY97 was expressed in all examined tissues and could be induced by various abiotic stresses and abscisic acid (ABA). OsWRKY97-GFP was localized to the nucleus. Various abiotic stress-related cis-acting elements were observed in the promoters of OsWRKY97. The results of OsWRKY97-overexpressing plant analyses revealed that OsWRKY97 plays a positive role in drought stress tolerance. In addition, physiological analyses revealed that OsWRKY97 improves drought stress tolerance by improving the osmotic adjustment ability, oxidative stress tolerance, and water retention capacity of the plant. Furthermore, OsWRKY97-overexpressing plants also showed higher sensitivity to exogenous ABA compared with that of wild-type rice (WT). Overexpression of OsWRKY97 also affected the transcript levels of ABA-responsive genes and the accumulation of ABA. These results indicate that OsWRKY97 plays a crucial role in the response to drought stress and may possess high potential value in improving drought tolerance in rice