Methyl Jasmonate, a Degreening Alternative for Mandarin (Citrus Reticulata L.) Var. Arrayana Fruits

Abstract

Mandarin accounts for a significant part of the Colombian citrus fruit production, the postharvest degreening of these products to attain pigmentation being a common practice when they are harvested in the tropics. The endogenous signaling molecules such as methyl jasmonate and ethylene are produced during fruit formation, and they play a key role in postharvest and stress responses. The latter is commonly used to degreen mandarin, which, however, exhibits low sensitivity to this compound. It is therefore important to establish degreening alternatives to ethylene. Thus, the aim of this study was to determine the effect of methyl jasmonate on the degreening of Arrayana mandarin (Citrus reticulata L.). For such purpose, respiration rate, weight loss, color index, total chlorophyll, total soluble solids, firmness and total acidity were determined. The treatments applied were: methyl jasmonate (MeJA) 1 µM 24h, Ethylene (ET) 1000 ppm 20 min, 1-methylcyclopropene (1-MCP) 0.5 µL L -1 2h; and the combinations 1-MCP + MeJA, 1-MCP + ET. Generally obtained with the MeJA and 1-MCP + MeJA treatments, the most significant results took place at 14 days after treatment implementation (DATI) for total titratable acidity, and at 4 DATI for total chlorophyll and color index. The TSS/acid ratio (maturity ratio) became constant since 7 DATI under the MeJA treatment. Thus, the use of MeJA after 1-MCP pretreatment comes to be an interesting degreening option, all the more when considering that these physiological responses have not been reported in previous studies.

Application of Methyl Jasmonate to Papaya Fruit Stored at Lower Temperature Attenuates Chilling Injury and Enhances the Antioxidant System to Maintain Quality

“…Nevertheless, MeJA-treated papaya fruits significantly reduced PWL as compared with the control group (Figure 1a), which might be ascribed to deferred respiration and transpiration. The presented data are in agreement with previous findings on radishes [51], 'Arrayana' mandarins [52], apricots [53], and kinnows [54], where MeJA application substantially reduced PWL by reducing the transpiration and maintaining membrane integrity. Furthermore, Liao et al [38] noticed a decrease in PWL and chilling injury symptoms in lemon fruit during storage following preand postharvest MeJA application ascribed to delayed metabolic activities and senescence.…”

Jasmonate activates a CsMPK6-CsMYC2 module that regulates the expression of β-citraurin biosynthetic genes and fruit coloration in orange (Citrus sinensis)

“…Similarly, the application of MeJA accelerated the coloration of fruit from tomato and mandarin that were treated with 1-MCP (i.e. fruit with attenuated ethylene signaling) ( Gómez et al, 2017 ; Rivero Meza et al, 2021 ). These authors proposed that JA uses an ethylene-independent mechanism to promote fruit coloration.…”

Pre- or Post-Harvest Treatment with MeJA Improves Post-Harvest Storage of Lemon Fruit by Stimulating the Antioxidant System and Alleviating Chilling Injury

“…The positive effect of pre- or post-application of MeJA on reducing CI in lemon fruit has been previously reported and is thought to be linked to enhanced antioxidant defense mechanisms [ 25 ]. Reduced weight loss has been shown for post-harvest applications of MeJa in ‘Arrayana’ mandarins [ 26 ]. This is supported by the results from this study which suggest that the control lemon fruit exhibited obvious CI symptoms after cold storage over 40 days at 7–10 °C, however, treatments with pre- or post-application of MeJA at three concentrations (0.1, 0.3, and 0.5 mM) alleviated the CI symptoms and WL of ‘Eureka’ lemons, with the most effective doses being pre MeJA at the concentration of 0.3 mM ( Figure 1 and Figure 2 ).…”