RNA sequencing in parthenocarpic chili pepper (Capsicum annuum) fruit reveals genes involved in transcriptional regulation of capsaicinoid biosynthesis genes responsible for the fluctuation of pungency
RNA sequencing in parthenocarpic chili pepper (Capsicum annuum) fruit reveals genes involved in transcriptional regulation of capsaicinoid biosynthesis genes responsible for the fluctuation of pungency
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DOI：
10.1016/j.scienta.2022.111456
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发表时间：
2022-12-15
影响因子：
4.3
通讯作者：
Matsushima, Kenichi
中科院分区：
文献类型：
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作者：
Kondo, Fumiya;Kumanomido, Yui;Matsushima, Kenichi
辣椒（Capsicum spp.）辣椒是一种受欢迎的园艺作物;辣椒特有的辣味是一类称为辣椒素的化合物的结果。在这种辣椒的园艺生产中，辣味的波动（辣椒素含量的变化）是一个重要的问题，因为这种波动会导致辣椒质量的分布混乱或恶化。在这里，我们试图澄清这种辛辣变化的机制，特别是通过在转录组水平上研究这种变化。本研究以辣味变异型甜椒品种“四桃”为材料，研究了辣椒辣度变异对辣椒品质的影响。annuum），并通过单性结实处理创造了高辛辣无核果实。RNA测序分析，然后被用来全面比较基因表达在这些水果中的种子少辛辣的水果。我们首先分析了辣椒素生物合成代谢途径的差异表达基因（DEG）。随后，我们采用聚类分析（使用先前发表的RNA测序数据），以探讨可能作为辣椒素类生物合成基因（CABG）的调节因子的编码推定的转录因子的基因的表达的变化。具体而言，我们筛选了9个具有与转录调控相关的基因本体的DEG（CaMYB 31、WRKY 9、TF 62308、TF 60920、TF 62062、TF 75838、ACOT 9、TF 62804和TF 64623），并发现这些DEG的表达模式与几种CABG的表达模式相似。我们还采用了定量逆转录聚合酶链反应，调查这些DEG的表达（在辛辣变化的水果）与假定的转录作用。因此，我们观察到这些DEG中的大多数的转录水平与胎盘隔膜中的辣椒素类物质的量正相关。因此，我们推测这些DEG与假定的转录调控作用参与辣椒素类物质的生物合成，这些DEG的转录水平可能有助于辣椒辛辣的波动。
Chili peppers (Capsicum spp.) are a popular horticultural crop; the characteristic hot taste of chili peppers is the result of a class of compounds called capsaicinoids. In the horticultural production of such peppers, fluctuations in pungency (changes in capsaicinoid content) are an important issue, given that this fluctuation can cause confusion in the distribution or deterioration of pepper quality. Here, we sought to clarify the mechanism of this variation in pungency, specifically by investigating this variation at the transcriptome level. In the present study, we used the pungency-variable sweet chili pepper 'Shishito' (C. annuum) and created high-pungency seedless fruits by parthenocarpic treatment. RNA-sequencing analysis then was used to comprehensively compare gene expression in these fruits with that in less-pungent seeded fruits. We firstly profiled differentially expressed genes (DEGs) contributing to metabolic pathways involved with capsaicinoid biosynthesis. Subsequently, we employed clustering analysis (using previously published RNA-sequencing data) to explore changes in the expression of genes encoding putative transcription factors that might serve as regulators of the capsaicinoid biosynthesis genes (CABGs). Specifically, we screened nine DEGs (CaMYB31, WRKY9, TF62308, TF60920, TF62062, TF75838, ACOT9, TF62804, and TF64623) that have gene ontology related to the regulation of transcription, and found that the expression patterns of these DEGs were similar to those of several CABGs. We also employed quantitative reverse transcriptional polymerase chain reaction to investigate the expression (in the pungency-varied fruits) of these DEGs with putative roles in transcription. Accordingly, we observed that the transcript levels in most of these DEGs correlated positively with the amount of capsaicinoid in the placental septum. Therefore, we postulate that these DEGs with putative transcriptional regulatory roles are involved in capsaicinoid biosynthesis, such that the transcript levels of these DEGs may contribute to the fluctuation of pepper pungency.