Plant cell ultrastructure, effect

Effect of Brassinosteroids on Protein Synthesis and Plant-Cell Ultrastructure under Stress... 

Pickett-Heaps, J.D. (1967). The effects of colchicine on the ultrastructure of dividing plant cells, xylem wall differentiation and distribution of cytoplasmic micrombules. Dev. Biol. 15, 206-236. 

Brassinosteroids (BSs) represent a new group of plant hormones that possess a broad spectrum of physiological activities (1,2). A most Intriguing property of BSs Is their capacity to Increase stress resistance In plants, but the mechanism of such an antistress activity still remains unknown (1). As cell stress resistance Is usually associated with stress protein synthesis (3 4) our aim was to study the BS effect on protein synthesis and ultrastructure of wheat leaf cells at normal temperature and under heat shock conditions. We have also studied the Influence of BSs on mesophyll cell ultrastructure under saline stress. 

BSs protected cereal leaf cells from heat shock or saline stress. Leaf pre treatment with BSs decreased cell ultrastructure degradation from heat shock and high salt conditions. BSs increased HSG formation which is supposed to protect preformed mRNA in plant cells during heating. BSs enhanced heat shook resistance of the leaf protein-synthesizing system. The effect of BSs on RNA and protein synthesis was shown earlier (14). We observed protein synthesis activation in wheat leaves by BSs in normal and under stress conditions. Two-dimensional SDS-FAAGE of dS-methionine labeled proteins demonstrated BS-induced changes in the set of polypeptides synthesized in leaves and in the rate of their synthesis. 

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