Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062, P.R. China.
State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, 430062, P.R. China.
BMC Plant Biol. 2023 Dec 7;23(1):626. doi: 10.1186/s12870-023-04656-3.
Glycosylation, catalyzed by UDP-glycosyltransferase (UGT), was important for enhancing solubility, bioactivity, and diversity of flavonoids. Peanut (Arachis hypogaea L.) is an important oilseed and cash crop worldwide. In addition to provide high quality of edible oils and proteins, peanut seeds contain a rich source of flavonoid glycosides that benefit human health. However, information of UGT gene family was quite limited in peanut.
In present study, a total of 267 AhUGTs clustered into 15 phylogenetic groups were identified in peanut genome. Group I has greatly expanded to contain the largest number of AhUGT genes. Segmental duplication was the major driving force for AhUGT gene family expansion. Transcriptomic analysis of gene expression profiles in various tissues and under different abiotic stress treatments indicated AhUGTs were involved in peanut growth and abiotic stress response. AhUGT75A (UGT73CG33), located in mitochondria, was characterized as a flavonoid 7-O-UGT by in vitro enzyme assays. The transcript level of AhUGT75A was strongly induced by abiotic stress. Overexpression of AhUGT75A resulted in accumulating less amount of malondialdehyde (MDA) and superoxide, and enhancing tolerance against drought and/or salt stress in transgenic Arabidopsis. These results indicated AhUGT75A played important roles in conferring abiotic stress tolerance through reactive oxygen species scavenging.
Our research only not provides valuable information for functional characterization of UGTs in peanut, but also gives new insights into potential applications in breeding new cultivars with both desirable stress tolerance and health benefits.
糖基化反应由 UDP-糖基转移酶（UGT）催化，对提高黄酮类化合物的水溶性、生物活性和多样性至关重要。花生（Arachis hypogaea L.）是世界范围内重要的油料作物和经济作物。除了提供高品质的食用油和蛋白质外，花生种子还含有丰富的类黄酮糖苷，有益于人类健康。然而，关于花生 UGT 基因家族的信息相当有限。
在本研究中，共鉴定出花生基因组中的 267 个 AhUGTs，分为 15 个系统发育组。第 I 组显著扩张，包含最多的 AhUGT 基因。片段重复是 AhUGT 基因家族扩张的主要驱动力。对不同组织和非生物胁迫处理下的基因表达谱进行转录组分析表明，AhUGTs 参与了花生的生长和非生物胁迫响应。位于线粒体的 AhUGT75A（UGT73CG33）通过体外酶实验被鉴定为黄酮类 7-O-UGT。AhUGT75A 的转录水平受到非生物胁迫的强烈诱导。过表达 AhUGT75A 导致丙二醛（MDA）和超氧自由基含量减少，增强了转基因拟南芥对干旱和/或盐胁迫的耐受性。这些结果表明，AhUGT75A 通过清除活性氧来发挥重要作用，赋予植物非生物胁迫耐受性。
本研究不仅为花生 UGT 的功能鉴定提供了有价值的信息，还为培育兼具理想抗逆性和健康效益的新品种提供了新的思路。
