Li Hongbo, Ma Xiaoling, Wang Weiqi, Zhang Jiaxi, Liu Yuanzhe, Yuan Deyi
Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees of the Ministry of Education, Central South University of Forestry and Technology, Changsha, China.
Front Plant Sci. 2023 Feb 24;14:1080946. doi: 10.3389/fpls.2023.1080946. eCollection 2023.
Abel. () is an important woody edible oil tree species in China. The quality of oil (tea oil) is mainly determined by the contents of linoleic acid (LA) and α-linolenic acid (ALA). However, how to increase the contents of LA and ALA in tea oil and the corresponding regulating mechanism have not been clarified. In the present study, we found that the LA and ALA contents in seeds were significant positively associated with the concentrations of ethephon and were decreased by ethylene inhibitor treatment. Furthermore, 1.5 g L ethephon could receive an optimal LA and ALA contents without adverse effects to the growth of 'Huashuo' trees in this study. The ethephon treatment also increased the contents of 1-aminocyclopropane-1-carboxylic acid (ACC), sucrose, soluble sugar and reducing sugar contents in seeds. Transcriptome analysis further suggested that exogenous ethephon application enhanced the accumulation of LA and ALA regulating genes involved in LA and ALA metabolism, plant hormone signal transduction pathways, and starch and sucrose metabolism. Our findings confirm the role of ethylene in LA and ALA regulation and provide new insights into the potential utilization of ethylene as a LA and ALA inducer in cultivation.
油桐是中国一种重要的木本食用油树种。桐油（茶油）的品质主要由亚油酸（LA）和α-亚麻酸（ALA）的含量决定。然而，如何提高茶油中LA和ALA的含量以及相应的调控机制尚未明确。在本研究中，我们发现桐籽中LA和ALA的含量与乙烯利浓度呈显著正相关，且经乙烯抑制剂处理后含量降低。此外，在本研究中，1.5 g/L乙烯利可使LA和ALA含量达到最佳，且对‘华硕’树的生长无不利影响。乙烯利处理还增加了种子中1-氨基环丙烷-1-羧酸（ACC）、蔗糖、可溶性糖和还原糖的含量。转录组分析进一步表明，外源施用乙烯利增强了参与LA和ALA代谢、植物激素信号转导途径以及淀粉和蔗糖代谢的LA和ALA调控基因的积累。我们的研究结果证实了乙烯在LA和ALA调控中的作用，并为乙烯作为LA和ALA诱导剂在油桐栽培中的潜在应用提供了新的见解。
