The molecular characterization and expression analyses of ethylene receptor genes from watermelon fruit

Abstract

Watermelon fruit is very sensitive to ethylene, showing rapid deterioration and water-soaking upon ethylene exposure. The objective of this study was to isolate and determine the expressions of ethylene receptor genes in watermelon fruit. As a result of PCR amplification of cDNAs obtained via RT-PCR of total RNA from watermelon fruit with degenerate primers, 3 partial cDNAs were obtained. After extension of the 3' and 5' ends of the cDNAs via 3' and 5' RACE analysis, 3 full-length genes designated as CL-ETR1, CL-ERS1, and CL-ETR2 were obtained. Upon cloning and sequencing, it was determined that the CL-ETR1, CL-ERS1, and CL-ETR2 genes were 2343, 2349, and 2550 bp in length, respectively. The structure and sequence analysis showed that the isolated genes had conserved domains found in previously isolated ETR genes. Southern blot analysis showed a single band for CL-ETR1 and CL-ETR2 and 2 bands for CL-ERS1. Northern blot analyses showed that the expression levels of all 3 receptor genes significantly increased during postharvest storage and in response to ethylene exposure. 1-Methylcyclopropene (1-MCP) treatment significantly reduced the expressions of all receptor genes. The genes also showed different expression patterns during fruit development. The isolated genes could be used in biotechnological studies to develop cultivars with altered ripening behavior that are more tolerant to ethylene-related physiological disorders such as water-soaking.

Genome-Wide Identification of Two-Component System Genes in Cucurbitaceae Crops and Expression Profiling Analyses in Cucumber

“…Thus, applying a systematic identification and functional study of these stress responsive genes is necessary to elucidate the molecular mechanisms of tolerance and susceptibility in Cucurbitaceae crops (e.g., cucumber and watermelon). So far, few TCS genes have been characterized in Cucurbitaceae crops (Yamasaki et al, 2000 ; Karakurt et al, 2014 ). Three ethylene receptors in cucumber belonged to HK(L) family, have been proved to participate in the formation and development of female flower (Yamasaki et al, 2000 , 2003 ; Wang et al, 2010 ).…”

The Role of 1‐Methylcyclopropene in the regulation of ethylene biosynthesis and ethylene receptor gene expression in Mangifera indica L. (Mango Fruit)

“…Li, Qiao, Tong, Zhou, and Zhang () showed that 1‐MCP upregulated the expression of the ETR3 gene in pear fruit 0 d–9 d after harvest and downregulated the expression of ERS2 6 d–15 d after harvest. Karakurt, Tonguç, and Ünlü () confirmed that 1‐MCP markedly decreased the expression levels of the ETR1 , ERS1 , and ETR2 genes in watermelons. Moreover, 1‐MCP has been broadly used to delay ripening and senescence in plants and to consequently extend the storage life of climacteric fruit.…”

Ethylene biosynthesis and signal transduction during ripening and softening in non-climacteric fruits: an overview

“…Non-climacteric fruits express many ethylene biosynthesis genes as well as a series of ethylene signaling components, such as ethylene receptors (ETRs), the negative regulator constitutive triple response (CTR1), and the transduction factors ethylene insensitive 2 (EIN2) and ethylene insensitive 3 (EIN3), EIN3-like (EIL), and ethyleneresponsive factor (ERF) (Osorio et al, 2012). Expression of these important signal transduction elements is upregulated to varying degrees during the ripening and softening processes of nonclimacteric fruits, as observed in strawberry (Trainotti et al, 2005;Sun et al, 2013;Qian et al, 2016), grape (Chervin and Deluc, 2010;Muñoz-Robredo et al, 2013;Qian et al, 2016;Ye et al, 2017), orange (Katz et al, 2004;Distefano et al, 2009;Wu et al, 2016;Kashyap and Banu, 2019), loquat (Aloś et al, 2017), cherry (Ren et al, 2011;Xanthopoulou et al, 2022), and watermelon (Karakurt and Huber, 2008;Karakurt et al, 2014). These findings indicate that ethylene indeed plays a critical role in regulating the ripening of nonclimacteric fruits.…”