TY - EJOU
AU - Che, Xiaoyu
AU - Wang, Yanlong
AU - Wang, Junling
AU - Liang, Linru
AU - Li, Yuxin
AU - Liu, Guoku
AU - Li, Yanhui
AU - Li, Ping
TI - The Role of Prohexadione-Calcium in Mediating the Alleviation of Shading Stress in Hesperis sibirica
T2 - Phyton-International Journal of Experimental Botany
PY -
VL -
IS -
SN - 1851-5657
AB - Shading stress significantly compromises the ornamental quality and ecological adaptability of Hesperis sibirica. To investigate the potential mitigating effects of plant growth regulators, this study systematically analyzed the regulatory mechanisms of foliar-applied prohexadione-calcium (Pro-Ca) at different concentrations (0, 100, 300, 600, and 900 mg·L−1) under both full sunlight and heavy shading (70% light reduction, retaining 30% of full sunlight intensity) conditions. Through comprehensive evaluation of plant morphological traits, chlorophyll content, photosynthetic parameters, and chlorophyll fluorescence characteristics, combined with structural observations using scanning electron microscopy, light microscopy, and transmission electron microscopy, 600 mg·L−1 Pro-Ca was identified as the optimal concentration for alleviating shading stress. This treatment significantly reduced plant height compared to the shading control, while also increasing floret number (50 d). During the observation period, the chlorophyll a/b ratio showed a notable improvement, accompanied by significant enhancements in the net photosynthetic rate (Pn) and maximum photochemical efficiency (Fv/Fm). Structural analysis revealed that this concentration promoted leaf thickening, stomatal optimization, and chloroplast ultrastructure repair. The comprehensive evaluation results confirmed that 600 mg·L−1 Pro-Ca provided the comparatively comprehensive regulatory effect under shading conditions.
KW - Chlorophyll fluorescence; membership function analysis; photosynthetic characteristics; shade adaptation; ultrastructure
DO - 10.32604/phyton.2026.086214