Scientific Papers Series B Horticulture

One of the first and simplest conditions toinfluence ethylene production refers to thehandling practices and storage temperature.When matter plants in general are subjected tophysical or biological stress the result may be atissue damage, which implies the production ofthe ethylene, either as a defense response or torepair the damage tissues. So, an increase ofrespiration and softening are registered (Mutariand Debbie, 2011). Tomato sealed in plasticfilms had an extended marketable life and itaffects the gaseous atmosphere around the fruit.The use of KMnO4 contributed to theproduction of CO 2 and water in the packageatmosphere which helped in lowering therespiration and ripening processes (Sammi andMasud, 2007). Post-harvest packing methods,such as storage in perforated (0.25%) polythenebags under ambient conditions (temperature of20 0 -25 0 C and relative humidity of 70-90%)extended up to 17 days tomato shelf lifewithout excessive quality decay (Nasrin et al.,2008). The use of black perforated polythenebags (Rahman et al., 2010), treating fruits withchloride and calcium chloride, and treatment of0.1% gibberellic acid and 0.4 nM salicylic acid(Pila et al., 2010) have been shown to decreasefruit decay and weight loss.There are also used some treatments in relationto ethylene management. For instance, postharvestapplication of 1-methylcyclopropene(1-MCP) as one of ethylene action inhibitor(Sisler, 2006) delayed tomato fruit ripening inrelation to the used concentration (Moretti etal., 2002). Response of various climacteric species,including tomato is variable and dependsalso on internal levels of ethylene (Zhang et al.,2009; Zhang et al., 2010). It should be consideredthat ingress and accumulation in tomatofruit of gaseous 1-MCP applied as gaseous oraqueous formulation is rapidly. The post-exposurefate is due in relation to multiple factors:inherent sorption-capacity, surface properties(e.g., waxes, stoma), volume and continuity ofgas-filled intercellular spaces, and tissue hydration(Dong et al., 2013). In addition, Su andGubler (2012) showed that reducing post-harvestdecay by 1-MCP is also associated with areduction of economic loss caused by diseases.There is also a positive interaction betweenjasmonates resulting from treatment withmethyl jasmonate (MeJA) and ethylene. MeJA425application causes increased jasmonates concentration,which regulate LOX activity associatedwith the production of superoxide anion,which has an impact on ethylene production(Yu et al., 2009). JA-ethylene cross-talk in theethylene synthesis pathways is based on theirsynergistic interaction, as for example the JAethyleneresponsive antifungal defensinPDF1.2 (Spoel et al., 2003) regulation by thesimultaneously activation of JA and ethyleneresponse pathways (Abeles et al., 1992). Kim etal. (2013) obtained contradictory results. Theynoticed that JA has also an inhibitory effect onethylene signaling, which may involve an EIN2(a key protein in ethylene signaling)-independentpathway. JA antagonistic and ethyleneindependently function was also registeredduring lycopene biosynthesis in tomato fruits(Liu et al., 2012).Respiration rate may be also controlled byinfluence its proper molecular mechanism.Alternative oxidase (AOX) and ethylene mediatefruit ripening of tomato. Xu et al. (2012)used tomato plants with reduced LeAOX (Lealternative oxidase) levels and results wereretarded ripening; reduced carotenoids, respiration,and ethylene production; and the downregulationof ripening-associated genes. On theother hand, the fruit that over expressedLeAOX1a accumulated more lycopene, andthey displayed a similar pattern of ripening towild-type fruit.Zhang et al. (2009) described a relationshipbetween ABA and ethylene during tomato fruitripening and senescence as followings: (i) theexpression of the ABA biosynthetic gene(LeNCED1) (which encode 9-cis-epoxy carotenoiddioxygenase (NCED) as a key enzyme inABA biosynthesis) occurs before that ofethylene biosynthesis genes; (ii) ABA contentalso preceded the climacteric increase inethylene production; (iii) ABA may induceethylene biosynthesis via the regulation of ACSand ACO gene expression; (iv) exogenousABA accelerates fruit ripening, and fluridoneor nordihydroguaiaretic acid treatment delayedfruit ripening by inhibition of ABA; and (v)ethylene plays a key role in the later stages offruit ripening.Delaying ripening and enhancing resistance toa post-harvest fungal pathogens can be alsoassure by NO treatments (Lai et al., 2011)