in plants. Jasmonates have diverse roles in plant growth and development and in plant responses to biotic and abiotic stress ( Wasternack, 2007 ). Methyl jasmonate has been evaluated as a potential abscission agent in several fruit crops ( Burns et al
Anish Malladi, Tripti Vashisth, and Lisa Klima Johnson
Xinhua Zhang, Fujun Li, Nana Ji, Shujun Shao, Dongyang Wang, Ling Li, and Fansheng Cheng
, the chambers were opened, and three lots of fruit were stored at 2 ± 1 °C with a relative humidity of 80% to 90% for up to 28 d. Fig. 1. Schematic diagram for tomato fruit treatment with methyl jasmonate (MeJA). Ten fruit were placed in a 9-L airtight
Hyoung Seok Kim and John A. Juvik
only two broccoli genotypes ( Robbins et al., 2005 ). We have investigated changes in Se and GS concentrations in five different broccoli cultivars after Se fertilization, MeJA treatments, or a combination of these treatments. Methyl jasmonate, a
1 E-mail email@example.com . I would like to thank Iskender Tiryaki for kindly supplying methyl jasmonate.
Ulrich Hartmond, Rongcai Yuan, Jacqueline K. Burns, Angela Grant, and Walter J. Kender
Methyl jasmonate (MJ) was tested as a potential abscission chemical to enhance mechanical harvest of `Hamlin' and `Valenica' orange [Citrus sinensis (L.) Osb.]. In field experiments, a solution of 1, 5, 10, 20, or 100 mm MJ was applied either as a stem wrap to individual fruit or as a spray to entire trees or canopy sectors. Solutions of 10, 20, and 100 mm MJ resulted in significant and consistent reduction of fruit detachment force and caused fruit drop within 7 to 10 days. Fruit loosening was preceded by an increase in the internal ethylene concentration of fruit similar to that of other experimental abscission compounds. While concentrations of 10 mm and less caused no or negligible phytotoxicity, solutions exceeding 10 mm MJ induced unacceptable levels of leaf abscission.
Raquel González-Herranz, Kimberley A. Cathline, Matthew W. Fidelibus, and Jacqueline K. Burns
1. Effect of methyl jasmonate (MeJA) treatment and days after treatment on fruit detachment force (FDF) of ‘Thompson Seedless’ grapes, Parlier, CA, 2007. Table 2. Effect of methyl jasmonate (MeJA) treatment and days after treatment
Kang Mo Ku and John A. Juvik
herbivory on flavonoids in broccoli ( Brassica oleracea var. italica Plenck) J. Appl. Bot. & Food Quality. 84 178 182 Kim, H.J. Chen, F. Wang, X. Choi, J.H. 2006a Effect of methyl jasmonate on phenolics, isothiocyanate, and metabolic enzymes in radish
Chien Yi Wang and J. George Buta
Freshly harvested unwaxed `Marsh Ruby' grapefruit (Citrus paradisi Macfad.) were obtained from Wabasso, Fla. The fruit were treated with methyl jasmonate by dipping, pressure infiltration (82.7 kPa for 3 minutes), or vapor fumigation. Control fruit were similarly treated with distilled water. All fruit were then stored at 1°C. Samples from all treatments were transferred to 20°C for 3 days after 4 and 10 weeks of storage at 1°C for evaluation of chilling injury. Symptoms of chilling injury were negligible in all treatments after 4 weeks of storage. However, after 10 weeks of storage, moderate to severe pitting occurred in the control fruit but the severity of chilling injury was significantly reduced by methyl jasmonate treatments. The most effective treatments were either pressure infiltration using a 0.1 mm emulsion or fumigation with vapor at saturation.
Xuetong Fan and James P. Mattheis
Climacteric `Fuji' apples (Malus ×domestica Borkh.) were treated with water, 0.45 mmol·m–3 1-methylcyclopropene (MCP), 2 mmol·L–1 methyl jasmonate (MJ), or both MCP and MJ. Fruit were kept at 20 °C for 17 days after treatment. Ethylene production, respiration, and color change were all inhibited following MCP treatment. Ethylene production following MJ treatment fluctuated below and above that of controls, but was representative of postclimacteric apples at all times. Rates of respiration and color change were enhanced by MJ, even when fruit were previously treated with MCP. The results indicate that MJ can enhance rate of color change and respiration in apple fruit independently of ethylene action.
J.K. Burns, U. Hartmond, R. Yuan, and W.J. Kender
Methyl jasmonate (Me-Ja) is a naturally occurring ubiquitous compound in plants. Me-Ja is considered to be a putative plant hormone because of its effect on plant processes such as senescence, germination, tuber formation, signal transduction, ethylene production, and abscission at low exogenous concentrations. We applied Me-Ja to fruit or whole trees of `Hamlin' or `Valencia' orange to determine the potential of this compound as a mature fruit abscission agent. Me-Ja (0, 1, 5, 10, or 20 mM in 0.1% Kinetic adjuvant) was applied to whole trees with a handgun or boom sprayer rates of 4850 and 1790 L·ha–1, respectively. Alternatively, tree fruit were dipped in Me-Ja solutions. Fruit drop, leaf drop and ethylene production in both fruit and leaves and fruit detachment force in fruit were monitored at various times up to 2 weeks after application. Me-Ja treatment resulted in increased ethylene production in fruit and leaves 1 to 2 days after application. Fruit detachment force significantly declined 6 to 10 days after application followed by significant fruit drop. Applications of Me-Ja >10 mM resulted in an unacceptable amount of canopy defoliation. The results suggest that Me-Ja has potential as an abscission agent for citrus. Future work will focus on improving uniformity of application and response.