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Barleria cristata L., commonly known as the Philippine violet, is native to South Asia. It is an ornamental plant and is also used for the treatment of a variety of diseases. In India, it is found throughout the country in many forms, varying in its floral attributes (calyx and corolla) and habitat. In order to understand the species limits in B. cristata, we studied morphological as well as palynological variation and assessed the phylogenetic relationships among five different morphotypes. The studied morphotypes (populations) came from three phytogeographical regions, namely the Western Ghats, the Deccan Peninsula and the Western Himalaya. The naturally occurring populations from the Deccan Peninsula and the Western Himalaya showed conspicuous differences in their morphology. All the morphotypes had oblate spheroidal, tri-brevicolporate and honey-combed pollen grains which differed only in their quantitative parameters. The distinct-looking morphotypes, namely, Nandi Hills, Uttarakhand and cultivated morphotypes, could not be separated based on pollen characters. Phylogenetic analyses based on chloroplast DNA sequences revealed that our samples formed a clade sister to the B. cristata specimen used in the previous study. The genetic variation within morphotypes was not enough for the genomic regions investigated; however, it revealed among morphotype genealogies in detail. Phylogenetic analyses showed that there were three monophyletic groups within the B. cristata complex that exhibited some morphological differences. Nevertheless, based on the present sampling, it is not possible to delimit these morphotypes at specific or infraspecific level. To reach such conclusions, further investigations like sampling this species across its distribution range in India and assessment of intraspecific relationships, and their cytogenetical characterization should be done.

Global projections on the climate change and the dynamic environmental perturbations indicate severe impacts on food security in general, and crop yield, vigor and the quality of produce in particular. Sessile plants respond to environmental challenges such as salt, drought, temperature, heavy metals at transcriptional and/or post-transcriptional levels through the stress-regulated network of pathways including transcription factors, proteins and the small non-coding endogenous RNAs. Amongs these, the miRNAs have gained unprecedented attention in recent years as key regulators for modulating gene expression in plants under stress. Hence, tailoring of miRNAs and their target pathways presents a promising strategy for developing multiple stress-tolerant crops. Plant stress tolerance has been successfully achieved through the over expression of microRNAs such as Os-miR408, Hv-miR82 for drought tolerance; OsmiR535A and artificial DST miRNA for salinity tolerance; and OsmiR535 and miR156 for combined drought and salt stress. Examples of miR408 overexpression also showed improved efficiency of irradiation utilization and carbon dioxide fixation in crop plants. Through this review, we present the current understanding about plant miRNAs, their roles in plant growth and stress-responses, the modern toolbox for identification, characterization and validation of miRNAs and their target genes including in silico tools, machine learning and artificial intelligence. Various approaches for up-regulation or knock-out of miRNAs have been discussed. The main emphasis has been given to the exploration of miRNAs for development of bioengineered climate-smart crops that can withstand changing climates and stressful environments, including combination of stresses, with very less or no yield penalties.