WATER STRESS IN CITRUS: DOES ENDOGENOUS ABA PLAY A REGULATORY ROLE?
Detached leaves are capable of rapid increase in endogenous ABA levels; upon rehydration both ABA levels and water potentials returned to pre-stress levels.
In potted seedlings the ABA-accumulating mechanism although present is less intense: accumulation is slow and levels attained are relatively lower. Rehydration is again effective.
Under orchard conditions it proved difficult to correlate changes in ABA levels and in water status.
The significance of the ABA-accumulating mechanism in citrus leaves is discussed.