engleski

ASR‐LIKE PROTEINS DETECTED IN IN VITRO‐GROWN CACTUS Mammillaria gracilis

Abscisic acid‐, Stress‐, and Ripening‐induced (ASR) proteins are plant specific, low molecular weight, heat‐stable proteins that have high hydrophilicity. ASR proteins were shown to possess transcription factor and chaperon‐like activities. They are involved in plant tolerance to drought and salinity, in regulation of sugar, branched amino acids and cell wall metabolism. The ASR protein family is widespread in the plant kingdom. However, the Arabidopsis as well as other Brassicaceae family species lack ASR genes, suggesting that ASR proteins are not ubiquitous to all plants. There is no knowledge if plants from the Cactaceae family, known for its highly tolerance to water stress, encode ASR proteins. We thus used in vitro‐grown M. gracilis tissues (plant, callus and tumor) in order to reveal if the ASR‐like proteins can be found in a member of the Cactaceae family. A SR proteins can be effectively purified to homogeneity on Ni‐NTA‐agarose, since they contain an authentic pentahistidine sequence close to their N‐termini. We thus applied ion chelating chromatography to purify ASR‐like protein from cactus tissues. Eluted proteins from Ni-agarose were analyzed by means of SDS‐PAGE, Native‐PAGE, western blot with anti‐ASR1 antibody and mass spectrometry. These analyses demonstrated, for the first time, that cacti encode ABA‐ and ripening‐induced proteins. Moreover, we revealed some possible interacting partners with cactus ASR‐like proteins which need to be further analyzed.

ASR proteins; cactus; plant tissue culture; mass spectrometry

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