Regulation of L-proline biosynthesis, signal transduction, transport, accumulation and its vital role in plants during variable environmental conditions

Abstract

BackgroundIn response to various environmental stresses, many plant species synthesize L-proline in the cytosol and accumulates in the chloroplasts. L-Proline accumulation in plants is a well-recognized physiological reaction to osmotic stress prompted by salinity, drought and other abiotic stresses. L-Proline plays several protective functions such as osmoprotectant, stabilizing cellular structures, enzymes, and scavenging reactive oxygen species (ROS), and keeps up redox balance in adverse situations. In addition, ample-studied osmoprotective capacity, L-proline has been also ensnared in the regulation of plant improvement, including flowering, pollen, embryo, and leaf enlargement.Scope and conclusionsAlbeit, ample is now well-known about L-proline metabolism, but certain characteristics of its biological roles are still indistinct. In the present review, we discuss the L-proline accumulation, metabolism, signaling, transport and regulation in the plants. We also discuss the effects of exogenous L-proline during different environmental conditions. L-Proline biosynthesis and catabolism are controlled by several cellular mechanisms, of which we identify only very fewer mechanisms. So, in the future, there is a requirement to identify such types of cellular mechanisms.

Response of Scenedesmus quadricauda (Chlorophyceae) to Salt Stress Considering Nutrient Enrichment and Intracellular Proline Accumulation

“…S. quadricauda showed the highest proline content at the different N:P ratios; N:P ratio of 20 in 6 and 12 psu and N:P ratio 10 at 0 and 3 psu, indicating that the salinity is also a factor to affect proline synthesis. The varying proline synthesis and growth rate with N and P addition suggest that S. quadricauda may require differential N:P ratios for its survival and population development under different salinity levels [26,38,41].…”

The Interaction Effect of Drought and Exogenous Application of Zearalenone on the Physiological, Biochemical Parameters and Yield of Legumes

“…Plant tissues have an efficiently functioning defense system against active forms of oxygen, consisting of enzymes that neutralize reactive oxygen species and interact with antioxidants. Excessive proline production is often observed in plants experiencing various types of stresses, especially drought, which is associated with a decrease in cell turgor (Kishor et al 2005;Ashraf and Foolad 2007;Gadzinowska et al 2019;Meena et al 2019). Despite numerous studies, there are still many uncertainties about the role of proline in the reaction of plants to abiotic factors.…”

Secondary Metabolites From Halotolerant Plant Growth Promoting Rhizobacteria for Ameliorating Salinity Stress in Plants

“…This catalytic reaction is stimulated by genes proB, proA, and proC (Kunst et al, 1997;Roy and Hill, 2002). Nitrogenfixing bacteria have been reported to show elevated proline metabolism due to increased activity of proline dehydrogenase (PDH) enzyme during salinity stress (Kohl et al, 1994;Meena et al, 2019). A HT-PGPR, Bacillus fortis SSB21, was reported to increase the levels of proline along with a reduction in lipid peroxidation and ROS, alongwith upregulation of stress regulating genes CAPIP2, CaKR1, CaOSM1, and CAChi2 in capsicum under saline conditions (1 and 2 g NaCl kg −1 soil) (Yasin et al, 2018).…”