Selenium: A Game Changer in Plant Development, Growth, and Stress Tolerance, via the Modulation in Gene Expression and Secondary Metabolite Biosynthesis

The presence of selenium(Se)is not widely established as crucial for crops,although it is commonly recognized as an important nutrient for animals as well as humans.Even so,it is inevitably accepted that Se usually contributes positively to the life cycle of plants.Previousfindings suggested that small amounts of Se seem to have a productive role in growth and production.As a result,Se is assumed to function in multiple ways,primarily by influencing a variety of biochemical and physiological functions.Also,Se also acts as a plant antioxidant and pro-oxidant and confers tolerance against different abiotic stresses,including salinity,drought,extreme temperature,and toxic metals/metalloids stresses.It reflects a defensive barrier against stress by increasing chlorophyll content synthesis,photosynthesis,oxygen supply,osmoprotectant concentration,and secondary metabolite acquisition.One other crucial role of Se is its ability to strengthen antioxidant performance in plants,thereby decreasing the concentration of reactive-oxygen-species(ROS).Furthermore,Se generates and modifies genes and proteins that respond situationally to stress,and the presence of high Se concentrations in the growth-medium can cause phytotoxic conditions via excessive ROS production,and through pro-oxidative Se occurrence,suppression of chlorophyll contents in the biosynthetic pathway,and the inhibition of plant developmental and normal physiological functions.Like a phytofortifier,the correct amount of Se can indeed enhance the nutrient quality of both crop and fodder production.Furthermore,crops have naturally developed ways to combat Se-deficiency and Se-toxicity.The current review focuses on recent advances in understanding the dynamics of Se,the positive and negative roles of Se in crop management,and its efficiency in countering abiotic stress.

Proteomic Profiling and Protein-Protein Interaction Network Reveal the Molecular Mechanisms of Susceptibility to Drought Stress in Canola(Brassica napus L.)

Drought stress is one of the most important abiotic stresses that plants face frequently in nature.Under drought conditions,many morphological,physiological,and molecular aspects of plants are changed and as a result plants experience a remarkable reduction in growth,yield,and reproduction.To expand our understanding of the molecular basis of the plant response to drought stress,the proteomic profile and protein-protein network of canola(Brassica napus L.)were studied.The focus was to show molecular mechanisms related to canola susceptibility to drought stress.The experiment used a completely randomized design,implemented in a hydroponic system under greenhouse conditions.To impose drought stress,plants were exposed to Hoagland’s solution supplemented with polyethylene glycol(PEG)6000 for 7 days.The drought stress resulted in 161reproducible protein spots in twodimensional electrophoresis of canola leaves.The t-student test showed 21 differentially abundant proteins(DAP),of which 2 and 19 were up and down accumulated,respectively.Two spots identified as 1-aminocyclopropane-1-carboxylate oxidase and D-2-hydroxyglutarate dehydrogenase showed an increased abundance of 2.11 and 1.77,respectively.The extended protein-protein interaction of differentially abundant proteins and KEGG analysis showed 47 pathways directly and indirectly associated with canola response to drought stress.DAPs with increased abundance were associated with amino acid and signaling processes,whereas DAPs with decreased abundance were mostly connected with pathways responsible for energy production.The results of the study will help to elucidate further the molecular events associated with the susceptibility to drought stress in canola.