TY  - EJOU
AU  - Zhang, Qinghao 
AU  - Yang, Yijie 
AU  - Wu, Jiong 
AU  - Li, Hongru 
AU  - Li, Yuan 
AU  - Li, Zuran 
AU  - He, Yongmei 

TI  - Enhanced Ultraviolet‑B Radiation Suppresses <i>Magnaporthe oryzae</i> Infection and Alleviates Its Damage to the Photosynthesis of Rice Leaves
T2  - Phyton-International Journal of Experimental Botany

PY  - 2024
VL  - 93
IS  - 10
SN  - 1851-5657

AB  - In the present study, an indoor potting experiment was conducted to study the effects of enhanced UV-B radiation and <i>Magnaporthe oryzae</i> on the growth, stomatal structure, photosynthesis, and endogenous hormone contents of a traditional rice cultivar Baijiaolaojing in the Yuanyang terraces of Yunnan Province. In addition, the relationships between these parameters and disease indices were analyzed. We aimed to clarify the response of the photosynthetic physiology of rice under the combined stress of UV-B radiation and <i>M. oryzae</i>. Compared with the <i>M. oryzae</i> infection treatment, all the treatments, including <i>M. oryzae</i> infection before (MBR), simultaneously with (MSR), and after (MAR) UV-B radiation significantly increased the rice height and biomass by 4%–11% and 30%–111%, respectively, and the stomatal structure and carotenoids content of leaves, while decreasing the contents of chlorophyll a and b, by 21%–41% and 63%–73%, respectively. Both the MSR and MBR treatments significantly increased the photosynthetic rate and transpiration rate of rice leaves. The MAR treatment weakened chlorophyll fluorescence parameters, including the actual photosystem II (PS II) photochemical efficiency, electron transport rate, photochemical quenching, and nonphotochemical quenching by 40%, 39%, 43%, and 24%, respectively. Moreover, the treatments of MAR, MSR, and MBR decreased the phytohormones content and the <i>M. oryzae</i> disease index by 27%–62% in rice leaves. Thus, the enhanced UV-B radiation contributed to suppressing the <i>M. oryzae</i> infection and alleviating its damage to the photosynthesis of rice leaves. This study is valuable for the control of rice blast fungus and offers important insights into plant pathology.
KW  - Rice; UV-B radiation; rice blast disease; hormones; plant responses

DO  - 10.32604/phyton.2024.056014