Antagonism between JA and cytokinin is of common occurrence in various plant growth and developmental processes. Cytokinin, benzyladenine (BA) has been reported to antagonize the effect of JA on root growth promotion in Solanum tuberosum (Sarkar et al., 2006). In cotyledons of sunflower (Helianthus annuus), MeJA promoted senescence, whereas pretreatment with cytokinin partially blocked MeJA-induced senescence (Mukherjee et al., 2002). Liu et al. (2015) concluded that exogenous applications of JA and cytokinin antagonistically regulated leaf senescence in O. sativa senescence associated genes expression. They also proposed that leaf senescence not only depends on the level of JA or cytokinin but also on the balance between JA and cytokinin (Liu et al., 2015). Earlier, Ananieva and Ananiev (2003) argued that MeJA promoted some aspects of senescence in intact Cucurbita pepo cotyledons partially due to down-regulation of endogenous levels of cytokinine levels and interconversion between active and inactive forms of cytokines (Ananieva and Ananiev, 2003). Apart from the above reports, antagonistic effect of cytokinins on the stimulatory effect of JAs has also been observed in potato tuber formation under in vitro conditions (Sarkar et al., 2006). A synergistic effect of JA and cytokinin has also been reported in T. aestivum to alleviate effects of salinity stress.
5.4. Jasmonates and abscisic acid
Several physiological and developmental processes in plants are influenced by JA