Effects Of Drought Treatment On The Regulation Mechanism Of Sugar Metabolism In Allium Mongolicum Seed During Germination

Drought stress can reduce seed germination rate.However,there are few reports on how sugar metabolism and related genes respond to drought stress during seed germination.In this study,we studied the expression of genes related to glucose metabolism and glucose metabolism pathway in germinating Allium mongolicum seeds under drought stress to elucidate the mechanism of response of Allium mongolicum seeds to drought environment.The main research results are as follows:(1)When the concentration of PEG-6000 solution was 5%,the seed germination was inhibited,but the germination rate and germination potential were still 40.66% and 22.66%,which indicated that the seed had certain germinating ability under mild drought stress;When PEG-6000 solution concentration reached 10%,the germination indexes were significantly inhibited,and the germination rate and germination potential were 23.33% and16%,respectively.When PEG-6000 solution concentration reached 20%,the germination rate and germination potential were only 15.33% and 2.67%.(2)The contents of soluble sugar,maltose,sucrose,fructose and glucose increased with the increase of drought stress.Under the same degree of drought stress,the contents of soluble sugar,sucrose,glucose and maltose decreased with the extension of stress time.(3)With the increase of drought stress,the activities of hexokinase,phosphofructokinase and pyruvate kinase increased significantly,which accelerated the glycolytic metabolism.However,the increase range of hexokinase,phosphofructokinase and pyruvate kinase in the seeds of C.chinensis was smaller than that on day 10 of drought stress at 5 days of drought stress.At the same time,the activities of citrate synthase and glucose-6-phosphate dehydrogenase increased with the intensification of drought stress.(4)Under the same degree of drought stress,ATP content decreased gradually with the extension of stress time,but the decreasing trend was not obvious,indicating that the demand for ATP content in the early stage of seed germination was higher than that in the later stage;At 5d and 10 d of drought stress,ATP content in the seeds of Allium mongolicum under each treatment increased with the increase of stress degree,and there were significant differences between the control and the other drought treatments.ATP content under 20%severe drought stress increased by 63.66% and 84.18% compared with the control,respectively.(5)Compared with severe drought stress,80 genes were differentially expressed in glycolysis/gluconeogenesis pathway at 5 days of drought stress,and one gene,Pdc A involved in pyruvate decarboxylate regulation,was only significantly up-regulated in this pathway,and this gene was not expressed at 10 days of drought stress.After 10 days of drought stress,a total of 84 genes were expressed in the glycolysis/gluconeogenesis pathway,and 3 genes were significantly up-regulated in this pathway.They were involved in glucose-6-phosphate 1-differential isomerase LOC100797902,pyruvate decarboxylase Pdc B and TRINITY＿DN69134＿c0＿g1＿i3＿1,respectively.The Pdc B gene was expressed at 5 and 10 days of drought stress,but the gene expression was not significant at 5 days of drought stress.(6)According to the composition pattern of amino acids,combined with gene ontology information,functional domain information and sequence evolution information and protein N-terminal sorting signals,the protein was subcellulated to speculate the specific presence of the protein in the cell.This study speculates that proteins XP＿051402652.1,AAM73539.1 and AAM73540.1 are distributed in mitochondria,and protein XP＿049107956.1 is distributed in cell membranes or vacuoles.