Objective Analysis of the response pattern of small heat shock protein (sHSP) gene Os02g0782500 to stress and hormones in rice (Oryza sativa) could provide theoretical basis for further research on the functions of Os02g0782500 in stress and hormone responses.

Method In this study, Os02g0782500 was cloned from 'Zhonghua 11' and bioinformatic analysis was performed. Quantitative real-time PCR (qRT-PCR) was used to analyze the expression patterns of Os02g0782500 in different tissues and under different hormones and abiotic stress treatments.

Result The gene Os02g0782500 had a coding region with a length of 519 bp, which encoded a small heat shock protein containing one conserved HSP20 domain. The phylogenetic analysis showed that Os02g0782500 was closely related to homologous proteins in maize and other monocotyledonous plants. The analysis of cis-acting elements showed that the promoter region of Os02g0782500 contained 28 plant hormone response cis-elements and 35 environmental stress response cis-elements. The qRT-PCR analysis showed that Os02g0782500 had the highest expression level in rice leaves. And the expression level of Os02g0782500 was induced by 6-BA, GA₃, IAA, high temperature, low temperature, PEG6000 and NaCl, which suggested that OS02G0782500 was essential for the abiotic stress responses in rice.

Conclusion This study clarified that the expression of Os02g0782500 was regulated by external factors such as high temperature, low temperature, 6-BA, GA₃ and IAA, which provided a foundation for the subsequent study of the biological function of Os02g0782500. It is suggested that Os02g0782500 may be involved in abiotic stress response of rice through IAA and other hormone signal transduction pathways.