硼诱导下番茄红素代谢关键基因表达特征

Characteristics of Key Gene Expression in Lycopene Metabolism Induced by Boron

微量元素硼参与作物的光合作用、糖的转化等多种生物代谢.糖和番茄红素是番茄果实的重要品质,但目前对于硼诱导下糖和番茄红素代谢关键酶基因表达变化研究尚少.采用大田试验研究不同供硼水平(0、1、2、4和8 mg/L硼砂)对‘凯丰’和‘红丽’两种番茄营养和风味品质的影响,运用转录组学和基因组学初步探究硼诱导的转录代谢信息,以及糖代谢关键基因和番茄红素合成关键基因的表达特征.结果显示,随着供硼水平的增加,两个品种番茄的产量较对照分别提高了27.3%~67.2%和22.2%~86.2%.转录组分析发现,硼处理下两个番茄品种的差异表达基因主要富集在生物过程中,部分差异基因还富集在番茄红素合成代谢通路和糖分合成代谢通路上.随着供硼水平的增加,在绿熟期番茄的糖代谢关键基因表达量整体上调,番茄红素合成关键基因PSY、PDS、ZDS、CrtISO表达量在绿熟期上调,Z-ISO基因表达量在成熟期上调.可溶性总糖与BA、NI基因的表达水平呈正相关,番茄红素含量与PSY、CrtISO基因表达量呈正相关.

The trace element boron is involved in a variety of biological metabolism such as photosynthesis and sugar conversion of crops.Sugar and lycopene are the important quality traits of tomato fruit,but there are still few studies on the changes of key enzyme genes expression in sugar and lycopene metabolism induced by boron.In this article,the effects of different boron supply levels(0,1,2,4 and 8 mg/L borax)on the nutritional and flavor quality of Kaifeng and Hongli tomatoes were studied by field experiments.Transcriptomics and genomics were used to preliminarily investigate the transcription and metabolism information induced by boron,as well as the expression characteristics of key enzyme genes for glucose metabolism and lycopene synthesis.The results showed that with the increase of boron supply level,the yield of tomatoes of both varieties showed an increasing trend,which increased by 27.3%-67.2%and 22.2%-86.2%compared with the control,respectively.Transcriptome analysis showed that the differentially expressed genes of the two tomato cultivars under boron treatment were mainly enriched in biological processes,and some differentially expressed genes were also enriched in the lycopene and sugar anabolic pathways.With the increase of boron supply level,the expression of key genes for sugar metabolism in tomatoes in the green ripening stage was upregulated.The expressions of key genes for lycopene synthesis,PSY,PDS,ZDS and CrtISO were upregulated in the green ripening stage,and the expression of Z-ISO gene was upregulated at the maturity stage.The correlation analysis showed that total soluble sugars were positively correlated with the expression levels of BA and NI genes,and lycopene content was positively correlated with the expression of PSY and CrtISO genes.