基于转录组研究葡萄糖对葡萄试管苗碳代谢的影响

Transcriptome Studies the Effect of Glucose on Carbon Metabolism of Grape Plantlets

通过转录组测序探究不同浓度(0、1%、2%和4%)外源葡萄糖对‘红地球’葡萄试管苗糖代谢和光合作用的影响。结果表明,2%葡萄糖处理下试管苗生长最好,其次是4%和1%处理,不添加葡萄糖的生长最弱。4个浓度下测序共获得了21.53 Gb Clean Data,Q30碱基百分比在89.49%以上。各样品与参考基因组的比对效率在68.31%～73.71%之间。单核苷酸多态性(Single Nucleotide Polymorphisms,SNP)的转换效率为64.73%～66.76%,颠换在33.24%～35.27%之间,且发生A?G和C?T突变类型最多。可变剪切类型中主要发生的是第一和最后一个外显子剪切事件。通过设定筛选差异基因的阈值,共获得了3 272个差异基因,包括下调基因2 826个和上调基因446个。在COG注释分类中,1%、2%和4%葡萄糖处理与0对照比对,分别注释到了1 449、846和597个差异基因,且大多数注释到除一般功能预测外,都是与转录相关的基因。对叶片碳代谢相关酶进行测定发现,蔗糖合成酶(SS)和葡萄糖6磷酸脱氢酶(G6PDH)活性随着葡萄糖处理浓度增加均表现出先减小后增加的趋势,且SS在4%葡萄糖处理中活性最高,而G6PDH在0对照中最高,中性转化酶(NI)和蔗糖磷酸合成酶(SPS)具有相同的变化趋势,两者的活性峰均出现在2%葡萄糖处理。经qRT-PCR验证,14个基因中有12个基因的表达趋势与转录测序结果一致,表明不同浓度葡萄糖通过影响叶片中碳代谢相关基因的表达来提高‘红地球’葡萄试管苗的生长。

The effects of glucose metabolism and photosynthesis on‘Red Globe’grape plantlets were studied under different concentrations(0,1%,2% and 4%)of exogenous glucose by the transcriptome sequencing. The result showed that the growth status of grape plantlets was the best under 2% glucose treatment,the second was 4% and 1%,the control(0)was the weakest in all treatments. 21.53 Gb Clean Data was obtained by sequencing in 4 different concentrations of glucose,and the base ratio of Q30 was more than 89.49%. Compared with reference genome,the sequence alignment efficiency was between 68.31% and 73.71% in all samples. The transfer efficiency of Single Nucleotide Polymorphisms(SNPs)ranged from 64.73% to 66.76%,and transversion was in 33.24%–35.27%. The most frequent types of mutations were A←→G and C←→T. The main event that occured in alternative splicing type was that the first and last exon were spliced. By setting a threshold to screening differentially express genes(DEGs),a total of 3 272 DEGs were obtained,including 2 826 down-regulated genes and 446 up-regulated genes. In the COG annotation classification,1%,2% and 4% were compared to the control,and annoted to 1 449,846 and 597 DEGs respectively,most of them are transcriptionally related genes except for general functional prediction. By detecting enzymes related leaf-carbon metabolism, SS and G6 PDH activities were decreased first,then increased when the glucose concentration was added more. SS and G6 PDH activities reached their peak value at 4% and 0,respectively. NI and SPS had same trend and both of their activity peak approached under the concentration of 2%. There was a consensus between expressional trend and sequenceing of 12 genes among 14 genes,indicating different concentrations of glucose regulate the expression of genes related leaf-carbon metabolism to improve the growth of‘Red Globe’.