Pretreatment by darkness increased chilling (4°C) injury in whole cotton (Gossypium hirsutum L.) seedlings and isolated cotyledonary tissue. Addition of sucrose in the dark period prevented the effect of darkness. Application of the photosynthetic inhibitor DCMU in light simulated the effect of darkness. ABA (10−5M) decreased chilling injury when applied in light as a pretreatment before the onset of chilling. The same pretreatment in darkness was almost ineffective, unless sucrose was added. ABA applied in light together with DCMU was ineffective in decreasing chilling injury. Lower light intensity resulted in increased chilling injury and a decreased effect of ABA in the prevention of chilling injury. The antimicrotubular drug colchicine increased the chilling injury. Pretreatment with ABA in light decreased the chilling and colchicine injury while the same pretreatment in darkness was ineffective. These results suggest that a deficiency of a photosynthetic product increases the chilling sensitivity of the tissue. ABA apparently increases chilling resistance through a metabolic process which depends on photosynthetic activity.
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Rikin et al. (1981) studied this question.