Comparative transcriptome analyses revealed differential strategies of roots and leaves from methyl jasmonate treatment Baphicacanthus cusia (Nees) Bremek and differentially expressed genes involved in tryptophan biosynthesis

Abstract

Baphicacanthus cusia (Nees) Bremek (B. cusia) is an effective herb for the treatment of acute promyelocytic leukemia and psoriasis in traditional Chinese medicine. Methyl jasmonate (MeJA) is a well-known signaling phytohormone that triggers gene expression in secondary metabolism. Currently, MeJA-mediated biosynthesis of indigo and indirubin in B. cusia is not well understood. In this study, we analyzed the content of indigo and indirubin in leaf and root tissues of B. cusia with high-performance liquid chromatography and measured photosynthetic characteristics of leaves treated by MeJA using FluorCam6 Fluorometer and chlorophyll fluorescence using the portable photosynthesis system CIRAS-2. We performed de novo RNA-seq of B. cusia leaf and root transcriptional profiles to investigate differentially expressed genes (DEGs) in response to exogenous MeJA application. The amount of indigo in MeJA-treated leaves were higher than that in controled leaves (p = 0.004), and the amounts of indigo in treated roots was higher than that in controlled roots (p = 0.048); Chlorophyll fluorescence of leaves treated with MeJA were significantly decreased. Leaves treated with MeJA showed lower photosynthetic rate compared to the control in the absence of MeJA. Functional annotation of DEGs showed the DEGs related to growth and development processes were down-regulated in the treated leaves, while most of the unigenes involved in the defense response were up-regulated in treated roots. This coincided with the effects of MeJA on photosynthetic characteristics and chlorophyll fluorescence. The qRT-PCR results showed that MeJA appears to down-regulate the gene expression of tryptophan synthase β-subunits (trpA-β) in leaves but increased the gene expression of anthranilate synthase (trp 3) in roots responsible for increased indigo content. The results showed that MeJA suppressed leaf photosynthesis for B. cusia and this growth-defense trade-off may contribute to the improved adaptability of B. cusia in changing environments.

Effects of exogenous methyl jasmonate on the synthesis of endogenous jasmonates and the regulation of photosynthesis in citrus

“…This study showed that MeJA could significantly improve F 0 , F m and F v /F 0 in Huangguogan and Shiranuhi at concentrations ≤2.2 mM, which was similar to results in soybean (Sirhindi et al 2016). However, 4.4 mM MeJA also inhibited the activity of the photosynthetic center, which was similar to the findings in Baphicacanthus cusia (Lin et al 2019).…”

“…Upon treatment with a low concentration of MeJA, the photosynthetic and transpiration rate in Huangguogan and Shiranuhi increased significantly, which was consistent with the results in cauliflower (Wu et al 2012). However, when the concentration of MeJA reached 4.4 mM, photosynthesis was significantly inhibited, similar to findings in Baphicacanthus cusia (Lin et al 2019) and S cutellaria baicalensis (Quan et al 2018). In addition, several other studies have shown that the photosynthetic rate of plants is dependent on the concentration of exogenous JAs in a non-linear fashion (Bali et al 2018, Agnihotri andSeth 2020).…”

“…Research in Pogostemon cablin (Li et al 2019) supported the negative feedback regulation of exogenous signals. Meanwhile, the results of transcriptome studies in Arabidopsis (Lin et al 2019) and bilberry (Benevenuto et al 2019) plants showed that no significant upregulation of JA-synthesizing genes was found in plants when an exogenous MeJA signal was actively given. Therefore, whether the physiological and biochemical regulation of plants in response to exogenous JAs stems from the direct receipt of exogenous signals or endogenous changes needs further confirmation according to the species under investigation.…”

Optimization of Extraction of Bioactive Compounds from Baphicacanthus cusia Leaves by Hydrophobic Deep Eutectic Solvents

“…Baphicacanthus cusia (Nees) Bremek is an herbal plant of the family Acanthaceae , mainly distributed in southern China, India and Myanmar. It is widely used as folk and clinical medicine [ 1 , 2 , 3 ]. The roots, stems and leaves of Baphicacanthus cusia can all be used as medicine and are commonly used in antiviral therapy.…”

Blue genome: chromosome‐scale genome reveals the evolutionary and molecular basis of indigo biosynthesis in Strobilanthes cusia

“…Since the SARS outbreak in 2003, interest in the antiviral properties of nanbanlangen has increased (Ni et al ., 2012), with particular recent attention being paid to the chemistry of S. cusia and the new indole alkaloids it contains (Lee et al ., 2019). Previous studies based on transcriptomic analysis revealed many candidate genes involved in the biosynthesis of indican backbone biosynthesis (Lin et al ., 2018, 2019).…”