Proline accumulation as a reliable indicator of monocarpic senescence in rice cultivars

Summary Proline content proportionally increased with leaf age as well as during aging in darkness of excised leaf segments collected from the flag, second and third leaves of the Jaya cultivar of rice. BA significantly suppressed, whereas ABA augmented, the rise of proline level in the leaf segments. Proline also increased in the attached flag, second and third leaves of all the 4 rice cultivars with the progress of reproductive development but the pattern of its accumulation was non-sequential in Jaya and Ratna and sequential in Masuri and Kalojira. Although proline accumulation was retarded and enhanced by treatment with BA and ABA, respectively, as foliar sprays, the mode of proline accumulation (non-sequential or sequential) remained unaltered.The financial assistance of the C.S.I.R., New Delhi, in the form of a research grant to MAC for carrying out the present investigation is acknowledged.