Liang Guoping, Li Yanmei, Wang Ping, Jiao Shuzhen, Wang Han, Mao Juan, Chen Baihong
College of Horticulture, Gansu Agricultural University, Lanzhou, China.
Front Plant Sci. 2022 Jun 22;13:920424. doi: 10.3389/fpls.2022.920424. eCollection 2022.
ADP-glucose pyrophosphorylase (AGPase) is a key rate-limiting enzyme involved in starch synthesis. APL1, an AGPase large subunit, plays an important role in the growth and development of grapes; however, its function in withstanding low temperature (LT) remains elusive. Hence, was cloned from (Zuoshan I), and its function was characterized. The gene was highly expressed in the phloem of during winter dormancy (0, -5, and - 10°C). Phylogenetic relationships demonstrated that VaAPL1 was closely genetic related to SlAPL1 (from ), and clustered into I group. Further, was ectopically expressed in (ecotype Columbia, Col) and tomato ("Micro-Tom" tomato) to characterize its function under LT. Compared with Col, the average survival rate of -overexpressing exceeded 75.47% after freezing treatment. Moreover, reactive oxygen species (ROS) content decreased in -overexpressing and tomato plants under LT stress. The activities of AGPase, and starch contents in -overexpressing were higher than in Col after LT stress. The contents of sucrose and glucose were accumulated in overexpressing plants compared with wild-type at 0 h and 24 h after LT stress. Transcriptome sequencing of overexpressing tomato plants revealed involvement in sugar metabolism and the hormone signal pathway, and Ca signaling pathway-related genes were up-regulated. Hence, these results suggest that overexpression of not only ensured sufficient starch converting into soluble sugars to maintain cell osmotic potential and provided energy, but also indirectly activated signal pathways involved in LT to enhance plant tolerance.
ADP - 葡萄糖焦磷酸化酶（AGPase）是参与淀粉合成的关键限速酶。APL1作为AGPase的大亚基，在葡萄的生长发育中起重要作用；然而，其在耐低温方面的功能仍不清楚。因此，从左山一号葡萄中克隆了该基因，并对其功能进行了表征。该基因在冬季休眠期（0、-5和 -10°C）的葡萄韧皮部中高表达。系统发育关系表明，VaAPL1与来自番茄的SlAPL1在遗传上密切相关，并聚类为第一组。此外，将该基因在拟南芥（生态型哥伦比亚，Col）和番茄（“Micro - Tom”番茄）中异位表达，以表征其在低温下的功能。与Col相比，过表达该基因的拟南芥在冷冻处理后的平均存活率超过75.47%。此外，在低温胁迫下，过表达该基因的拟南芥和番茄植株中的活性氧（ROS）含量降低。低温胁迫后，过表达该基因的拟南芥中AGPase的活性和淀粉含量高于Col。与野生型相比，在低温胁迫后0小时和24小时，过表达植株中蔗糖和葡萄糖的含量积累。对过表达番茄植株的转录组测序显示其参与糖代谢和激素信号通路，并且与钙信号通路相关的基因上调。因此，这些结果表明，该基因的过表达不仅确保了足够的淀粉转化为可溶性糖以维持细胞渗透势并提供能量，还间接激活了参与低温的信号通路以增强植物耐受性。
