Recent developments in therapeutic protein expression technologies in plants.

Infectious diseases and cancers are some of the commonest causes of deaths throughout the world. The previous two decades have witnessed a combined endeavor across various biological sciences to address this issue in novel ways. The advent of recombinant DNA technologies has provided the tools for producing recombinant proteins that can be used as therapeutic agents. A number of expression systems have been developed for the production of pharmaceutical products. Recently, advances have been made using plants as bioreactors to produce therapeutic proteins directed against infectious diseases and cancers. This review highlights the recent progress in therapeutic protein expression in plants (stable and transient), the factors affecting heterologous protein expression, vector systems and recent developments in existing technologies and steps towards the industrial production of plant-made vaccines, antibodies, and biopharmaceuticals.

Disease resistance in rice and the role of molecular breeding in protecting rice crops against diseases.

Rice diseases (bacterial, fungal, or viral) threaten food productivity. Host resistance is the most efficient, environmentally friendly method to cope with such diverse pathogens. Quantitative resistance conferred by quantitative trait loci (QTLs) is a valuable resource for rice disease resistance improvement. Although QTLs confer partial but durable resistance to many pathogen species in different crop plants, the molecular mechanisms of quantitative disease resistance remain mostly unknown. Quantitative resistance and non-host resistance are types of broad-spectrum resistance, which are mediated by resistance (R) genes. Because R genes activate different resistance pathways, investigating the genetic spectrum of resistance may lead to minimal losses from harmful diseases. Genome studies can reveal interactions between different genes and their pathways and provide insight into gene functions. Protein­protein interaction (proteomics) studies using molecular and bioinformatics tools may further enlighten our understanding of resistance phenomena.

Potential role of phytohormones and plant growth-promoting rhizobacteria in abiotic stresses: consequences for changing environment.

Plants are sessile beings, so the need of mechanisms to flee from unfavorable circumstances has provided the development of unique and sophisticated responses to environmental stresses. Depending on the degree of plasticity, many morphological, cellular, anatomical, and physiological changes occur in plants in response to abiotic stress. Phytohormones are small molecules that play critical roles in regulating plant growth and development, as well as stress tolerance to promote survival and acclimatize to varying environments. To congregate the challenges of salinity, temperature extremes, and osmotic stress, plants use their genetic mechanism and different adaptive and biological approaches for survival and high production. In the present attempt, we review the potential role of different phytohormones and plant growth-promoting rhizobacteria in abiotic stresses and summarize the research progress in plant responses to abiotic stresses at physiological and molecular levels. We emphasized the regulatory circuits of abscisic acid, indole acetic acid, cytokinins, gibberellic acid, salicylic acid, brassinosteroids, jasmonates, ethylene, and triazole on exposure to abiotic stresses. Current progress is exemplified by the identification and validation of several significant genes that enhanced crop tolerance to stress in the field. These findings will make the modification of hormone biosynthetic pathways for the transgenic plant generation with augmented abiotic stress tolerance and boosting crop productivity in the coming decades possible.