玉米二酰甘油激酶基因耐低温分析OA

Diacylglycerol kinase(DGK)catalyzes the conversion of diacylglycerol(DAG)to phosphatidic acid(PA),participating in plant responses to various abiotic stresses.This study employed CRISPR/Cas9 technology to knock out the ZmDGK1 gene in maize(Zea mays L.),generating zmdgk1CR T3 homozygous lines(with inbred line B104 as the genetic transformation recipient).Three zmdgk1CR lines and B104 were subjected to low-temperature stress,and their phenotypic and physiological indicators were measured.Results showed that the zmdgk1CR seedlings exhibited less severe leaf chlorosis,yellowing,and wilting.Root growth was only slightly inhibited,with total root length increased by 11.30%-16.17%compared to that of B104.Analysis of low-temperature tolerance-related physiological indicators revealed significant differences between the zmdgk1CR lines and B104 in parameters related to reactive oxygen species,cell membrane damage,antioxidant enzyme activity,osmotic regulators,and photosynthetic pigments.Specifically,the zmdgk1CR lines exhibited a 24.61%-30.71%reduction in O2-.content and a 5.19%-18.18%reduction in malondialdehyde content,while showing a 3.31%-19.88%increase in superoxide dismutase activity and an 8.78%-27.23%increase in total chlorophyll content.Furthermore,DAB,NBT,H2DCF-DA,and PI staining of leaves and roots from zmdgk1CR lines after low-temperature treatment confirmed that ZmDGK1 gene deletion reduced reactive oxygen species accumulation and mitigated cell membrane damage,while enhancing antioxidant capacity of maize,osmotic regulation,and photosynthetic pigment accumulation.These findings collectively indicate that the ZmDGK1 gene negatively regulates low-temperature tolerance in maize seedlings.