Signal transduction pathways under abiotic stresses in plants.

摘要

All abiotic stresses reduce plant growth and yield. The products of stress-inducible genes which could be directly protecting against these stresses include the enzymes responsible for the synthesis of various osmoprotectants like late embryogenesis abundant (LEA) proteins, antifreeze proteins, chaperones and detoxification enzymes. Another group of gene products involved in gene expression and signal transduction pathways includes transcription factors, protein kinases and enzymes involved in phosphoinositide metabolism. In the present article, the signal transduction pathways involving mitogen-activated protein kinases (MAPK) under osmotic/oxidative stress are presented. Studies indicate that in addition to connections between MAPK modules used by osmotic stress and ROS signalling, there is also specificity in the individual pathways. The role of external stimuli and of IP3 as a second messenger in releasing Ca+2 from cellular stores is reported. The interaction between phosphoinositide-specific phospholipase C activity and IP3 level is indicated. Abiotic stresses and ABA biosynthesis suggested connection between cold, drought, salinity and ABA signal transduction pathways. Calcium-dependent signalling that leads to LEA type genes and salt overly sensitive signalling that result in ion homeostasis is discussed. Crosstalk among various transduction pathways under abiotic stresses in regulation of metabolism has been reviewed..