Jasieniecka-Gazarkiewicz Katarzyna, Klińska-Bąchor Sylwia, Banaś Antoni
Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, 80-307, Poland.
BMC Plant Biol. 2025 Jul 2;25(1):809. doi: 10.1186/s12870-025-06922-y.
One of the most common abiotic stressors for plants is cold temperature and the principal adaptation of plant cells to this stressor is the remodeling of membranes fluidity. In the present studies we investigated the role of acyl-CoA: lysophatidylethanolamine acyltransferases (LPEAT), one of the enzymes involved in phospholipids re-synthesis and remodeling, in Arabidopsis plants adaptation to cold temperature.
Arabidopsis control plants and mutants with knockout and overexpression of the AtLPEAT1 and AtLPEAT2 were grown under cold and standard temperatures (4 °C and 21 °C respectively) and their development was monitored. Both overexpressors produced higher biomass of the rosettes than control plants (wild-type; WT) and the rosettes of lpeat2 and lpeat1xlpeat2 mutants were much smaller than WT plants. Unexpectedly, lpeat1 mutant developed bigger rosettes than WT plants. All lpeat mutants showed prolonged senescence of rosettes leaves and delayed start of flowering than WT plants. Contrary to growth under standard temperature, the LPEAT1-OE, lpeat2 and lpeat1 x lpeat2 mutants cultivated under low temperature exhibited yellow-green colour, in contrast to dark green colour of leaves of WT, LPEAT2-OE and lpeat1 mutant. Biochemical analyses of photosynthetic pigments showed greater differences in their content and composition in analysed Arabidopsis lines cultivated under cold temperature than under standard temperature. In all lpeat mutants, decrease in the amount of all analysed lipid classes per unit of fresh weight was detected, however, it was the most pronounced in the case of phosphatidylglycerol (PG) and monogalactosyldiacylglycerol (MGDG). The strong correlation between different expression levels of genes encoding LPEAT enzymes, in the tested plant lines, and the LPEAT and LPGAT activity (lysophoshatidylethanolamine and lysophoshatidylglycerol serve as fatty acid acceptors, respectively) were noted. This type of correlation concerned also remodelling intensity of phosphatidylethanolamine (PE) and PG.
The study has shown that the previously observed effects of overexpression and knockout of LPEAT genes occur independently of cultivation condition, and that the cold temperature modifies these effects and brings new anomalies. They showed also that LPEAT enzymes are important (in some cases indispensable) in the remodelling of PE and PG and in the re-synthesis of PG.
低温是植物最常见的非生物胁迫因素之一，植物细胞对这种胁迫的主要适应方式是膜流动性的重塑。在本研究中，我们调查了酰基辅酶A：溶血磷脂酰乙醇胺酰基转移酶（LPEAT）在拟南芥适应低温过程中的作用，LPEAT是参与磷脂重新合成和重塑的酶之一。
将拟南芥对照植株以及AtLPEAT1和AtLPEAT2基因敲除和过表达的突变体分别在低温和标准温度（分别为4°C和21°C）下培养，并监测其生长发育情况。两个过表达植株莲座叶的生物量均高于对照植株（野生型；WT），而lpeat2和lpeat1xlpeat2突变体的莲座叶比WT植株小得多。出乎意料的是，lpeat1突变体的莲座叶比WT植株大。所有lpeat突变体的莲座叶衰老时间延长，开花起始时间比WT植株延迟。与在标准温度下生长不同，在低温下培养的LPEAT1-OE、lpeat2和lpeat1 x lpeat2突变体呈现黄绿色，而WT、LPEAT2-OE和lpeat1突变体的叶片为深绿色。光合色素的生化分析表明，与标准温度下相比，在低温下培养的拟南芥品系中，光合色素的含量和组成差异更大。在所有lpeat突变体中，每单位鲜重中所有分析的脂质种类的含量均下降，然而，磷脂酰甘油（PG）和单半乳糖基二酰甘油（MGDG）的下降最为明显。我们注意到，在测试的植株品系中，编码LPEAT酶的不同表达水平与LPEAT和LPGAT活性（溶血磷脂酰乙醇胺和溶血磷脂酰甘油分别作为脂肪酸受体）之间存在很强的相关性。这种相关性也涉及磷脂酰乙醇胺（PE）和PG的重塑强度。
该研究表明，先前观察到的LPEAT基因过表达和敲除的效应与培养条件无关，低温会改变这些效应并带来新的异常现象。研究还表明，LPEAT酶在PE和PG的重塑以及PG的重新合成中很重要（在某些情况下是不可或缺的）。
