Yu Jiaxuan, Tang Lu, Qiao Fei, Liu Juhua, Li Xinguo
School of Tropical Agriculture and Forest, Hainan University, Haikou 570228, China.
National Key Laboratory for Tropical Crop Breeding, Haikou 570228, China.
Plants (Basel). 2024 Mar 3;13(5):712. doi: 10.3390/plants13050712.
Exogenous methyl jasmonate (MeJA) application has shown promising effects on plant defense under diverse abiotic stresses. However, the mechanisms underlying MeJA-induced stress resistance in bananas are unclear. Therefore, in this study, we treated banana plants with 100 μM MeJA before inducing osmotic stress using mannitol. Plant phenotype and antioxidant enzyme activity results demonstrated that MeJA improved osmotic stress resistance in banana plants. Thereafter, to explore the molecular mechanisms underlying MeJA-induced osmotic stress resistance in banana seedlings, we conducted high-throughput RNA sequencing (RNA-seq) using leaf and root samples of "Brazilian" banana seedlings treated with MeJA for 0 h and 8 h. RNA-seq analysis showed that MeJA treatment upregulated 1506 (leaf) and 3341 (root) genes and downregulated 1768 (leaf) and 4625 (root) genes. Then, we performed gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses on the differentially expressed genes. We noted that linoleic acid metabolism was enriched in both root and leaf samples, and the genes of this pathway exhibited different expression patterns; genes were highly induced by MeJA in the leaves, whereas genes were highly induced in the roots. We also identified the promoters of these genes, as the differences in response elements may contribute to tissue-specific gene expression in response to MeJA application in banana seedlings. Overall, the findings of this study provide insights into the mechanisms underlying abiotic stress resistance in banana that may aid in the improvement of banana varieties relying on molecular breeding.
外源茉莉酸甲酯（MeJA）处理在多种非生物胁迫下对植物防御表现出了有前景的效果。然而，MeJA诱导香蕉抗逆性的潜在机制尚不清楚。因此，在本研究中，我们在使用甘露醇诱导渗透胁迫之前，用100μM MeJA处理香蕉植株。植株表型和抗氧化酶活性结果表明，MeJA提高了香蕉植株的渗透胁迫抗性。此后，为了探究MeJA诱导香蕉幼苗渗透胁迫抗性的分子机制，我们对用MeJA处理0小时和8小时的“巴西”香蕉幼苗的叶片和根样本进行了高通量RNA测序（RNA-seq）。RNA-seq分析表明，MeJA处理上调了1506个（叶片）和3341个（根）基因，并下调了1768个（叶片）和4625个（根）基因。然后，我们对差异表达基因进行了基因本体论和京都基因与基因组百科全书分析。我们注意到，亚油酸代谢在根和叶样本中均富集，且该途径的基因表现出不同的表达模式；叶片中的基因被MeJA高度诱导，而根中的基因被高度诱导。我们还鉴定了这些基因的启动子，因为响应元件的差异可能有助于香蕉幼苗中响应MeJA处理的组织特异性基因表达。总体而言，本研究结果为香蕉非生物胁迫抗性的潜在机制提供了见解，这可能有助于依靠分子育种改良香蕉品种。
