Comparative Transcriptomic Analysis Provides Novel Insights into the Blanched Stem of Oenanthe javanica.

Sunjeet Kumar,Hongwei Hou,Qun Ji,Xinfang Huang,Guopeng Zhu,Honglian Zhu,Kai Zhou,Jingjing Yang,Gaojie Li,Weidong Ke

doi:10.3390/plants10112484

Abstract

In the agricultural field, blanching is a technique used to obtain tender, sweet, and delicious water dropwort stems by blocking sunlight. The physiological and nutritional parameters of blanched water dropwort have been previously investigated. However, the molecular mechanism of blanching remains unclear. In the present study, we investigated transcriptomic variations for different blanching periods in the stem of water dropwort (pre, mid, post-blanching, and control). The results showed that many genes in pathways, such as photosynthesis, carbon fixation, and phytohormone signal transduction as well as transcription factors (TFs) were significantly dysregulated. Blanched stems of water dropwort showed the higher number of downregulated genes in pathways, such as photosynthesis, antenna protein, carbon fixation in photosynthetic organisms, and porphyrin and chlorophyll metabolism, which ultimately affect the photosynthesis in water dropwort. The genes of hormone signal transduction pathways (ethylene, jasmonic acid, brassinosteroid, and indole-3-acetic acid) showed upregulation in the post-blanched water dropwort plants. Overall, a higher number of genes coding for TFs, such as ERF, BHLH, MYB, zinc-finger, bZIP, and WRKY were overexpressed in blanched samples in comparison with the control. These genes and pathways participate in inducing the length, developmental processes, pale color, and stress tolerance of the blanched stem. Overall, the genes responsive to blanching, which were identified in this study, provide an effective foundation for further studies on the molecular mechanisms of blanching and photosynthesis regulations in water dropwort and other species.

Highlights

We found that upregulation of many ethylene related genes in the blanched stems of water dropwort, and we speculate that it has an important role in response to blanching conditions, plant developmental processes, and pale coloration of stem
The transcriptomic response to blanching of water dropwort stem are presented based on Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses, and PlantTFDB
The generated data provides a basis for further studies on the transcriptomic response to blanching and photosynthesis in water dropwort and other related species

Summary

Introduction

Commonly known as water dropwort belongs to the family Apiaceae. It is a perennial aquatic vegetable mostly cultivated in several countries, including China, Japan, Korea, and Thailand [1,2,3]. It is a rich source of several vitamins, minerals, dietary fiber, phenolics, and flavonoids. It is used to treat fever, mumps, jaundice, hypertension, leucorrhea, haematuria, and abdominal pain [1,2,4]. Phytochemicals present in water dropwort, such as persicarin, apigenin, isorhamnetin, quercetin, and hyperoside have different pharmacological activities, such as anticancer, anti-hepatitis

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Conclusion