Influence of Shade on Plant Hormone Profiling in Rare and Endangered Plant Emmenopterys henryi Oliv. Based on Transcriptomic Analysis

Environmental light intensity is vital for natural regeneration and the population size of rare and endangered plant Emmenopterys henryi Oliv. Clarifying the effect of shade on hormone metabolism and signaling in leaf, stem and root will contribute to illumination of the endangerment mechanism of E. henryi. Results indicated that indole-3-acetic acid (IAA) level increased in leaf and root under 10% of full light intensity while decreased in stem under shade. Trans-zeatin (tZ) content fell in leaf whereas rose in stem and root under 10% of full light intensity. Isopentennyladenine (iP) level was immune to shade in leaf whereas peaked under 40% of full light intensity in stem and root. 1-Aminocyclopropane-1-carboxylic acid (ACC) content in leaf, stem or root lifted with the increase of shade degree. Salicylic acid (SA) concentration decreased in leaf or stem under 40 or 10% of full light intensity, respectively, while ascended in root under shade. Jasmonic acid-isoleucine (JA-Ile) level decreased in leaf or stem but changed little in root under shade. The genes related to metabolism and signaling of IAA, CK, ACC, SA and JA were significantly regulated by shade. The hub genes obtained by WGCNA analysis included those encoding AP2/ERF, GRAS, bZIP25, NAC, TGA, C3HC4-type RING finger proteins E3 ligases, WRKY40, WRKY50, WRKY70, WRKY41, bHLH61, bHLH162, bHLH18, bHLH90, bHLH137, MYB4, MYB118, C2H2-type zinc finger protein, Dof zinc finger protein, expansin and xyloglucan endotransglucosylase/hydrolase, further research into which will be helpful for illumination of the adaptation mechanism of E. henryi to shade.