Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China.
Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, 315211, Zhejiang, China.
Mar Environ Res. 2022 Jul;179:105688. doi: 10.1016/j.marenvres.2022.105688. Epub 2022 Jun 20.
High temperatures seriously limit the growth and productivity of Gracilariopsis lemaneiformis. By hydrolyzing glycerolipids into lysophospholipids (LPs) and free fatty acids (FFAs), patatin-like phospholipase A (pPLA) plays an important role in stress responses. GlpPLA expression was up-regulated under heat stress, however, the regulation of pPLA in heat tolerance of G. lemaneiformis is unknown. In this study, G. lemaneiformis under heat stress was treated with bromoenololide (BEL), a chemical inhibitor of pPLA, to evaluate the cellular function of pPLA in this species. When pPLA was inhibited through BEL treatment, the sensitivity of G. lemaneiformis to heat stress increased and the biomass and maximum and effective quantum yield of photosystem II decreased. Moreover, BEL treatment resulted in a significant decrease in many lipid molecular species, all of which are mainly composed of 16C, 18C, and 20C fatty acids. Consistently, FFA levels and LPs contents in G. lemaneiformis under BEL treatment showed a significant decrease. The first step in the synthesis of jasmonic acid (JA) is the lipoxygenase (LOX)-mediated oxygenation of linolenic acid (C18:3). BEL treatment decreased JA and C18:3 accumulation and markedly downregulated the expression of GILOX under heat stress. Together, these results indicate that pPLA is closely related to the growth of G. lemaneiformis under heat stress, and pPLA is involved in the lipid metabolism and JA biosynthesis of G. lemaneiformis in response to heat stress. This research broadens the understanding of the heat stress adaptation mechanism of G. lemaneiformis.
高温严重限制了掌状海带的生长和生产力。通过将甘油脂质水解为溶血磷脂（LPs）和游离脂肪酸（FFAs），类脂酶 PLA（pPLA）在应激反应中发挥重要作用。热胁迫下 GlpPLA 的表达上调，但 pPLA 对掌状海带耐热性的调控尚不清楚。在这项研究中，用 patatin-like phospholipase A（pPLA）的化学抑制剂溴烯醇内酯（BEL）处理热胁迫下的掌状海带，以评估 pPLA 在该物种中的细胞功能。当通过 BEL 处理抑制 pPLA 时，掌状海带对热胁迫的敏感性增加，生物量和光系统 II 的最大和有效量子产量降低。此外，BEL 处理导致许多脂质分子种类显著减少，这些脂质主要由 16C、18C 和 20C 脂肪酸组成。一致地，BEL 处理下掌状海带中的游离脂肪酸（FFA）水平和溶血磷脂（LPs）含量显著下降。茉莉酸（JA）合成的第一步是脂氧合酶（LOX）介导的亚麻酸（C18:3）氧化。BEL 处理降低了 JA 和 C18:3 的积累，并显著下调了热胁迫下 GILOX 的表达。总之，这些结果表明 pPLA 与热胁迫下掌状海带的生长密切相关，pPLA 参与了掌状海带对热胁迫的脂质代谢和 JA 生物合成。这项研究拓宽了对掌状海带热应激适应机制的理解。
