Chen Wenliang, Dong Tao, Chen Yinglong, Lin Ping, Wang Chuqiao, Chen Kelin, Tang Yi, Wang Mingyuan, Liu Jianfu, Yu Hailing
Institute of Horticulture Science and Engineering, Huaqiao University, Xiamen, 361021, China.
Institute of Fruit Tree ResearchKey Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization, Ministry of Agriculture and Rural AffairsGuangdong Provincial Key Laboratory of Tropical and Subtropical Fruit Tree Research, Guangdong Academy of Agricultural Sciences, Guangzhou, 510640, China.
Plant Mol Biol. 2022 Dec;110(6):531-543. doi: 10.1007/s11103-022-01304-6. Epub 2022 Aug 13.
Potassium (K) has an important effect on the growth and development of plants. Banana contains higher K content than many other fruits, and its plant requires more K nutrient in soil. However, the soil in the banana-producing areas in China is generally deficient in K. Therefore, understanding the mechanism of banana K absorption may assist in providing effective strategy to solve this problem. This study used two banana varieties with contrasting K tolerance, 'Guijiao No. 1' (low-K tolerant), and 'Brazilian banana' (low-K sensitive)to investigate K absorption mechanisms in response to low-K stress through miRNA and mRNA sequencing analysis. Under low-K condition, 'Guijiao No.1' showed higher plant height, dry weight, tissue K content and ATPase activity. Analysis of transcription factors showed that they were mainly in the types or classes of MYB, AP-EREBP, bHLH, etc. The sequencing results showed that 'Guijiao No. 1' had 776 differentially expressed genes (DEGs) and 27 differentially expressed miRNAs (DEMs), and 'Brazilian banana' had 71 DEGs and 14 DEMs between normal and low K treatments. RT-qPCR results showed that all miRNAs and mRNAs showed similar expression patterns with RNA-Seq and transcriptome. miRNA regulatory network was constructed by integrated analysis of miRNA-mRNA data. miR160a was screened out as a key miRNA, and preliminary functional validation was performed. Arabidopsis overexpressing miR160a showed reduced tolerance to low K, and inhibited phenotypic traits such as shorter root length, and reduced K accumulation. The overexpressed miR160a had a targeting relationship with ARF10 and ARF16 in Arabidopsis. These results indicate that miR160a may regulate K absorption in bananas through the auxin pathway. This study provides a theoretical basis for further study on the molecular mechanism of banana response to low potassium stress.
钾（K）对植物的生长发育具有重要影响。香蕉的钾含量高于许多其他水果，其植株在土壤中需要更多的钾养分。然而，中国香蕉产区的土壤普遍缺钾。因此，了解香蕉钾吸收机制可能有助于提供解决这一问题的有效策略。本研究使用两个钾耐受性不同的香蕉品种，即“桂蕉1号”（耐低钾）和“巴西蕉”（低钾敏感），通过miRNA和mRNA测序分析来研究低钾胁迫下的钾吸收机制。在低钾条件下，“桂蕉1号”表现出更高的株高、干重、组织钾含量和ATP酶活性。转录因子分析表明，它们主要属于MYB、AP-EREBP、bHLH等类型或类别。测序结果显示，在正常和低钾处理之间，“桂蕉1号”有776个差异表达基因（DEGs）和27个差异表达miRNA（DEMs），“巴西蕉”有71个DEGs和14个DEMs。RT-qPCR结果表明，所有miRNA和mRNA的表达模式与RNA-Seq和转录组相似。通过对miRNA-mRNA数据的综合分析构建了miRNA调控网络。筛选出miR160a作为关键miRNA，并进行了初步功能验证。过表达miR160a的拟南芥对低钾的耐受性降低，抑制了根长缩短和钾积累减少等表型性状。过表达的miR160a与拟南芥中的ARF10和ARF16具有靶向关系。这些结果表明，miR160a可能通过生长素途径调节香蕉的钾吸收。本研究为进一步研究香蕉对低钾胁迫响应的分子机制提供了理论依据。
