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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Publications at this Location » Publication #351038
Title: Over-expression of Oshox4 enhances drought and salinity tolerance in rice

Author
item ZHOU, WENQI - Gansu Academy Of Agricultural Sciences
item ZHOU, YUQIAN - Gansu Academy Of Agricultural Sciences
item HE, CUNYU - Gansu University Of Chinese Medicine
item Mou, Beiquan
item Zhou, Wei

Submitted to: Russian Journal of Plant Physiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/13/2020
Publication Date: 10/18/2020
Citation: Zhou, W.Q., Zhou, Y.Q., He, C.Y., Mou, B., Zhou, W. 2020. Over-expression of Oshox4 enhances drought and salinity tolerance in rice. Russian Journal of Plant Physiology. 67:1152-1162. https://doi.org/10.1134/S1021443720060205.
DOI: https://doi.org/10.1134/S1021443720060205

Interpretive Summary: Water and salt stresses are major yield-limiting factors in rice production worldwide. The homeodomain leucine zipper (HD-Zip) proteins are encoded by genes involved in adaptation to abiotic stresses. Our previous work characterized the HD-Zip family gene Oshox4 (Homobox4) as an important regulator of a plant growth hormone gibberellic acid. Here we investigated the role of rice Oshox4 gene for drought and salt stress tolerance. Our observations showed that Oshox4 transgenic lines displayed a higher level of tolerance to drought and salt stress compared to non-transgenic plants. To explain the strong stress tolerance of Oshox4 transgenic lines, we studied the expression of many rice gene families and found that these families were very active under severe drought and salt stress conditions in Oshox4 transgenic plants. Our results confirmed the role of Oshox4 in rice osmatic tolerance and provided new insight on maintaining a higher yield under water-limited situation by improving physiological conditions.

Technical Abstract: The homeodomain leucine zipper (HD-Zip) proteins are encoded by genes involved in adaptation to abiotic stresses. Our previous work characterized the HD-Zip family I gene Oshox4 (Homobox4) as an important regulator of gibberellic acid (GA) deactivation by controlling the expression of rice DELLA subfamily genes, rice GA 2-oxidase and GA 3-oxidase genes. Here we investigated the role of rice Oshox4 gene for drought and salt stress tolerance. Phenotypic analysis showed that Oshox4 transgenic lines displayed a higher level of tolerance to drought and salt stress compared to non-transgenic IR64 plants. To explain the strong osmotic stress tolerance of Oshox4 transgenic lines, we studied the expression of rice GA 2-oxidase, rice YABBY, rice KRP, and rice GRAS gene families. qRT-PCR results showed that OsGA2ox4, OsGA2ox6, OsGA2ox8, OsGAI and OsSCRL were highly expressed under severe drought in Oshox4 transgenic plants. Oshox4 enhanced the expression of OsGA2ox5, OsKRP2 and OsKRP5 under 50mM salt treatment and OsCRL under 200mM salt treatment. Our results confirmed the role of Oshox4 in rice osmatic tolerance and provided new insight on maintaining a higher yield under water-limited situation by improving physiological conditions.