RICE ADAPTS TO ALKALI STRESS BY MICROSTRUCTURAL CHANGES

HAIXIN ZHAO; XIAODONG DU; SHUQIANG CHEN; LIMIN YANG; FENG PENG; XIAOQUN HUANG; WENDONG MA; HAIYAN ZHENG; YONGSHENG CAI; GUOJUN PAN

doi:10.30848/PJB2022-4(13)

Response of four rice varieties namely Suijing 5, Longjing 27, Fujisawa 138, and Koshihikari to salt-alkali stress can assist in understanding the physiological and molecular mechanisms of salt-alkali stress. The sensitivity differences of microstructural changes under alkali stress between different rice varieties were examined and found that the alignment and integrity of root cells of different varieties of rice were compromised by alkali stress. The root cells of Longjing 27 were more sensitive to alkali stress, and its morphology more easily changed. In different rice varieties the formation of branch roots, the proportion of vascular columns and large vascular bundles in the root cross-section were increased along with the increase of the diameter of the vascular column and large vascular bundles, and maintained consistent transport of nutrients to compensate for the root function. In all resistance to alkali stress was chloroplasts and mitochondria were also affected by alkali stress, while Suijing 5 was more resistant to alkali stress. Chloroplast structure and function in Suijing 5 were relatively intact. Suijing 5 could still complete photosynthesis but could not complete the transport of synthetic products. The structure and function of mitochondria and chloroplasts in the other three rice species were severely impaired, and photosynthesis and product transportation were blocked. Suijing 5 was the best alkali resistant rice variety according to microstructural analysis.