Cloning of 9-cis-epoxycarotenoid dioxygenase (NCED) gene and the role of ABA on fruit ripening

Abstract

In order to understand more details about the role of abscisic acid (ABA) in fruit ripening and senescence, six 740 bp cDNAs (LeNCED1, LeNCED2, PpNCED1, VVNCED1, DKNCED1 and CMNCED1) which encode 9-cis-epoxycarotenoid dioxygenase (NCED) as a key enzyme in ABA biosynthesis, were cloned from fruits of tomato, peach, grape, persimmon and melon using an RT-PCR approach. A Blast homology search revealed a similarity of amino acid 85.76% between the NCEDs. A relationship between ABA and ethylene during ripening was also investigated. At the mature green stage, exogenous ABA treatment increased ABA content in flesh, and promoting ethylene synthesis and fruit ripening, while treatment with nordihydroguaiaretic acid (NDGA), inhibited them, delayed fruit ripening and softening. However, ABA inhibited the ethylene synthesis obviously while NDGA promoted them when treated the immature fruit with these chemicals. At the breaker, NDGA treatment cannot block ABA accumulation and ethylene synthesis. Based on the results obtained in this study, it was concluded that ABA plays different role in ethylene synthesis system in different stages of tomato fruit ripening. IntroductionBecause the plant hormone abscisic acid (ABA) displays a pattern of change similar to ethylene at late stages of fruit development, it was considered that ABA had a crucial role, perhaps even more crucial role than that of ethylene, in fruit maturation and senescence. 1-3 However, had not demonstration of molecular level. To date, the ripening mechanism of climacteric fruit, especially the effect of ethylene, has been well studied, 4 while the mechanism involved in the ripening of non-climacteric fruits remains unclear. However, the two types of fruits exhibit the same ripening phenomena in terms of colour and texture, with only a difference in ethylene production. On the other hand, ABA can be considered as the ripening control factor, because the ABA content is very low in unripe fruit but increases during the process of fruit ripening in both climacteric 5,6 and non-climacteric fruits. 7-10 At present, a relationship between ABA and ethylene during ripening and senescence was indicated in the tomato fruit: (i) the expression of the ABA biosynthetic gene (LeNCED1) occurs before that of ethylene biosynthesis genes; (ii) ABA content also preceded the climacteric increase in ethylene production; (iii) ABA may induce ethylene biosynthesis via the regulation of ACS and ACO gene expression; (iv) exogenous ABA accelerates fruit ripening, and fluridone or NDGA treatment delayed fruit ripening by inhibition of ABA; and (v) ethylene plays a key role in the later stages of fruit ripening. 11 Also, in our experimental of peach and grape fruits, the potential contribution of ABA was analyzed, in relation to ethylene, in the induction of fruit ripening in both species. The results demonstrated: (1) PpNCED1 and VVNCED1 initiated ABA biosynthesis at the beginning of fruit ripening in peach and grape, respectively, (2) ABA accumulation preceded the climacteric raise in et...

A Comprehensive Analysis of Carotenoid Cleavage Dioxygenases Genes in Solanum Lycopersicum

“…The SlCCD8 has the highest expression in the tomato root, followed by the stem and old leaves. The expression pattern of CCD8 genes in tomato is consistent with the expression pattern of homologous CCD8 gene in other plant species, indicating the existence of the conservation of potential function among CCD8 genes (Ledger et al 2010;Pasare et al 2013;Zhang et al 2009b). Finally, the SlCCD-like gene, one of the new classes of CCD genes, was detected in the root, stem, bud, flower, pistil, and mature green fruit.…”

“…These NCED cleave 9-cis isomers of epoxycarotenoids at the 11,12 position to yield xanthoxian, which is the precursor of abscisic acid biosynthesis (Zhang et al 2009a, b ). In Arabidopsis, each member of the NCEDs (NCED2, NCED3, NCED5, NCED6, and NCED9) plays a different role in controlling the biosynthesis of ABA, as well as its responding various stress and biological functions (Auldridge et al 2006a;Zhang et al 2009b). …”

Age-induced loss of wound-healing ability in potato tubers is partly regulated by ABA

“…While 9-cis-epoxycarotenoid dioxygenase (NCED) plays a key role in ABA synthesis in plants (Zhang et al 2009;Xiong and Zhu 2003), catabolism is mediated by ABA-8Ј-hydroxylase, which converts ABA into phaseic acid (Cutler and Krochko 1999;Kushiro et al 2004;Saito et al 2004). The eightfold out-of-storage diVerence in ABA content of 6-and 18-month-old tubers (Fig.…”

Ripening of Tomato Fruit and Susceptibility to Botrytis cinerea

“…The effect of ABA for the outcome of particular plant-pathogen interactions depends on the organisms, the developmental stage of the host and/or the environmental conditions in which the interaction occurs (Mauch-Mani and Mauch 2005 ;Ton et al 2009 ;Robert-Seilaniantz et al 2011 ). ABA regulates aspects of ripening in climacteric as well as non-climacteric fruit (Zhang et al 2009 ;Koyama et al 2010 ;Jia et al 2011 ;Soto et al 2013 ). In tomato fruit, ABA activates ripening because it enhances the expression of ethylene biosynthetic genes from System 2 (Zhang et al 2009 ).…”

“…ABA regulates aspects of ripening in climacteric as well as non-climacteric fruit (Zhang et al 2009 ;Koyama et al 2010 ;Jia et al 2011 ;Soto et al 2013 ). In tomato fruit, ABA activates ripening because it enhances the expression of ethylene biosynthetic genes from System 2 (Zhang et al 2009 ). ABA also triggers senescence in vegetative tissues and possibly in fruit (Lee et al 2011 ).…”