Identification And Functionality Of Starch Accumulation-related Genes Induced By Alternative Photoperiods In Potato

Different genotypes of the same species in long-day or short-day can lead to the starch accumulation starting time and accumulation are significant differences.There is no doubt that change the response of plants to the circadian cycle and early start of accumulation is one of the options to increase starch accumulation.However, currently research on how plants respond to photoperiod in gene expression levels are poorly understood. In this experiment, we used different photoperiods leaves of potato as materials, by transcriptome sequencing to identify starch accumulation-related genes induced by alternative photoperiods in potato results were as following:(1) Identify a total of 27,022 transcripts under long, short-day and a control treatment sample by sequencing analysis. the average length of the transcripts sequence is 1640bp. Among 27,022 transcripts has 22,033 coexpressin genes under the light treatment,19,935 coexpressin genes under the dark treatment; KEGG enrichment analysis showed that 121 metabolic pathways involved in the long and short day treatment.(2) GO functional annotation and differentiation gene analysis (DEG), screened upstream key response genes 1,985; which had 208 treatment specific DNA binding (TSDB) Genes, used part of the short-day treatment TSDBs gene qPCR quantitative analysis, results showed that the expression fold change were consistent with its RPKM.(3) Under different photoperiod,17 starch biosynthesis enzymes encoding genes show significant differential expression; Among it four genes in the light was significantly higher than dark, one in the dark was significantly higher than light; Bioinformatics analysis showed that AP2 transcription factors, etc were directly involved in the initiation of transcription of 17 genes.(4) Cloned EPIDERMAL PATTERNING FACTOR 2 (EPF2), YABBY-like transcription factor GRAMINIFOLIA (GRAM) and the cup-shaped protein 3 (CUC3) gene full-length cDNA, and constructed 6 fusion genes, which achieve the purpose of inhibiting and overexpression in potatos.(5) Screened epf2+and epf2-positive transformed lines, stomatal imprint observations, the stomatal of epf2+and epf2-positive transformed lines showed complex opening and closing modes, inhibiting and overexpression of EPF2 interact with photoperiod to regulate stomatal opening and closing.(6) Determination of starch content results showed, in different photoperiods the starch accumulation of epf2+showed a consistent trend with control; The starch accumulation of epf2-lines had a significant reduction under LL(long light) treatment; in CL and SL, the starch accumulation of epf2-lines was opposite with control, so the starch accumulation under darkness was significantly higher than light.