Abstract: Plants of ap ricot (DT: drought-tolerance genotype Prunus armeniaca L. var. Ansu Maxim.
and DS: drought-sensitive genotype Prunus arm eniaca vulgaris Lam. ‘Longwangmao’) were grown in pots of
peat2based compost in order to examine the role of JA under drought stress. GC /MS analysis indicated that JA
levels in leaves increased by 3 times in DT on day 12 since waterwithheld while it showed very little variation
in the whole drying period in DS. There was no significant detectable difference in the concentration of JA in
roots of well2watered and unwatered two ap ricot p lants. The LOX activity in old leaves of both increased while
waterwaswithheld. However, the LOX activity in roots of two ap ricot p lants showed very little variation in the
experiment. Exogenous JA accelerated senescence of leaves in ap ricots by p igment loss. After this drying peri
od, the p lants were rewatered. Two months after rewatering, twelve of the eighteen DT lived, whereas all of
the eighteen DS died. These results suggest that the transient accumulation of JA from leavesmay be necessary
to p romote leaf senescence due to soil drying.

Key words: Apricot, Drought stress, Jasmonic acid, Senescence, Leaf