Transcriptome Analysis Revealed a Positive Role of Ethephon on Chlorophyll Metabolism of Zoysia japonica under Cold Stress

Abstract

Zoysia japonica is a warm-season turfgrass with a good tolerance and minimal maintenance requirements. However, its use in Northern China is limited due to massive chlorophyll loss in early fall, which is the main factor affecting its distribution and utilization. Although ethephon treatment at specific concentrations has reportedly improved stress tolerance and extended the green period in turfgrass, the potential mechanisms underlying this effect are not clear. In this study, we evaluated and analyzed chlorophyll changes in the physiology and transcriptome of Z. japonica plants in response to cold stress (4 °C) with and without ethephon pretreatment. Based on the transcriptome and chlorophyll content analysis, ethephon pretreatment increased the leaf chlorophyll content under cold stress by affecting two processes: the stimulation of chlorophyll synthesis by upregulating ZjMgCH2 and ZjMgCH3 expression; and the suppression of chlorophyll degradation by downregulating ZjPAO, ZjRCCR, and ZjSGR expression. Furthermore, ethephon pretreatment increased the ratio of chlorophyll a to chlorophyll b in the leaves under cold stress, most likely by suppressing the conversion of chlorophyll a to chlorophyll b due to decreased chlorophyll b synthesis via downregulation of ZjCAO. Additionally, the inhibition of chlorophyll b synthesis may result in energy redistribution between photosystem II and photosystem I.

The Effect of Ethephon on Ethylene and Chlorophyll in Zoysia japonica Leaves

“…As a direct ethylene source, ethephon is applied to plants and elicits a response identical to that induced by ethylene gas, for evaluating the impact of ethylene on plants [44,45]. Studies have confirmed that ethephon can indeed function as ethylene and improve the cold resistance of plants [46,47]. Moreover, in our previous studies, ethephon could reduce the chlorophyll loss of Z. japonica under cold stress, and a transcriptome analysis showed that ethephon regulated chlorophyll biosynthesis and degradation [47].…”

Comprehensive transcriptomic analysis of age-, dark-, and salt-induced senescence reveals underlying mechanisms and key regulators of leaf senescence in Zoysia japonica

“…It is commonly employed as a decorative cover in diverse settings, including gardens, parks, sport fields, and golf courses. However, Z. japonica , despite its popularity, exhibits an early yellowing phenotype in the fall ( Zhang et al., 2022 ). The shortness of its green period can be mitigated through controlling senescence ( Guan et al., 2022a ), and therefore delaying leaf senescence may be an effective means of extending the green phase of Z. japonica and thereby enhancing its economic value.…”

Transcriptome analysis of the Bactrian camel (Camelus bactrianus) reveals candidate genes affecting milk production traits

“…DEGs were identified between different comparison groups (WDL vs WGH, RSQ vs CRQ) using the DESeq2 package in R (version 4.2.1) based on negative binomial distribution. Considering previous studies [ 31 , 32 ] and our specific experimental situation, adjusted P -values ( P -adjust) < 0.05 and |log2FoldChange|> 0 were established as the thresholds for significance. Adjusted P -values were calculated using the Benjamini–Hochberg method.…”