Salicylic acid (SA) has been implicated in determining the outcome of interactions between many plants and their pathogens. Global changes in response to this phytohormone have been observed at the transcript level, but little is known of how it induces changes in protein abundance. To this end we have investigated the effect of 1 mM SA on soluble proteins of Arabidopsis thaliana leaves by proteomic analysis. An initial study at transcript level has been performed on temporal landscape, which revealed that induction of most of the SA-responsive genes occurs within 3 to 6 h post treatment (HPT) and the expression peaked within 24 HPT. Two-dimensional gel electrophoresis (2-DE) coupled with MALDI-TOF MS/MS analysis has been used to identify differentially expressed proteins and 63 spots have been identified successfully. This comparative proteomic profiling of SA treated leaves versus control leaves demonstrated the changes of many defence related proteins like pathogenesis related protein 10a (PR10a), disease-resistance-like protein, putative late blight-resistance protein, WRKY4, MYB4, etc. along with gross increase in the rate of energy production, while other general metabolism rate is slightly toned down, presumably signifying a transition from ‘normal mode’ to ‘defence mode’.

Plant developmental biology is associated with various gene regulatory pathways involved in different phases of their lifecycle. In course of development, growth and differentiation of different organs in plants are regulated by specific sets ofgene expression. With the advances in genomic and bioinformatic techniques, particularly high-throughput sequencingtechnology, many transcriptional units with no protein-coding potential have been discovered. Previously thought to be thedark matters of genome, long non-coding RNAs (lncRNAs) are gradually gaining importance as crucial players in generegulation during different developmental phases. Some lncRNAs, showing complementarity to microRNAs (miRNAs), areused as endogenous target mimics of specific miRNA family. A number of lncRNAs can also act as natural antisensetranscripts to attenuate the expression of coding genes. Although lncRNA-mediated regulations have extensively beenstudied in animals, plant lncRNA research is still in its initial phase. The present review highlights the regulatory mechanismand different physiological aspects of lncRNAs in plant development. In plants, lncRNAs are found to be associatedwith a number of plant developmental functions such as lateral root development, vernalization, photomorphogenesis,pollen development, fiber development and nodulation. Understanding these potent roles of lncRNAs in plant developmentcan further provide novel tools for crop improvement programs in future.