G proteins are the key regulators for a wide range of cellular processes in animals and plants.
In comparison to animals and yeast plants have a single Rho-GTPase subfamily called Rho-like
GTPases (ROPs). The ROP family of monomeric GTPases has emerged as a versatile and key
regulator in plant signal transduction processes. During the past few years' studies on plant
RHO-type (ROP) GTPase have generated new insights into their role in diverse processes ranging
from cytoskeletal organization polar growth development to stress and hormonal responses.
Studies have shown that plants have evolved specific regulators and effector molecules. ROP
GTPases possess the ability to interact with these multiple regulator and effector molecules
that ultimately determines their signaling specificity. Recently genome wide studies in plants
have shown that the Arabidopsis genome encodes 93 and rice has nearly 85 small GTPase
homologs. And we have been able to identify four new homologs in the rice genome. Here we
focus on the complete phylogenetic domain structural and expression analysis during stress
and various developmental processes of small GTPases in plants. The comparison of gene
expression patterns of the individual members of the GTPase family may help to reveal potential
plant specific signaling mechanisms and their relevance. Also we are summarizing the role of
currently known ROP GTPases and their interacting proteins with brief description
simultaneously comparing their expression pattern based on microarray data. Overall we will
be discussing the functional genomic perspective of plant Rho like GTPases and their role in
regulating several physiological processes such as stress hormonal pollen tube root
hair-growth and other developmental responses.
