Salicylic Acid Improves Nitrogen Fixation,Growth, Yield and Antioxidant Defence Mechanisms in Chickpea Genotypes Under Salt Stress

Journal of Plant Growth Regulation - Salinization of farming soils is a major abiotic stress hampering crop growth and productivity globally. Chickpea is a vital legume crop, being cultivated...     

Influence of zinc on cadmium-induced toxicity in nodules of pigeonpea (Cajanus cajan L. Millsp.) inoculated with arbuscular mycorrhizal (AM) fungi

Arbuscular mycorrhizal (AM) fungi are known to alleviate heavy-metal stress in plants. The intent of the present work was to analyze accumulation of heavy metals (Cd and Zn) in nodules of two Cajanus cajan (L.) Millsp. genotypes and their subsequent impact on nitrogen fixation, oxidative stress, and non-protein thiols (glutathione and phytochelatins) with and without AM fungus Glomus mosseae. Accumulation of Cd and Zn in nodules resulted in sharp reduction in nodule number, nodule dry mass as well as nitrogen fixation (leghemoglobin and nitrogenase (N₂ase)), although Cd had more pronounced effects than Zn. Cd-induced lipid peroxidation, H₂O₂ accumulation, and electrolyte leakage were largely reversed by Zn supplementation. Zn application significantly altered the negative effects of Cd on the synthesis of non-protein thiols, suggesting antagonistic behaviour of Zn. Higher concentration of Zn was more effective in lessening the negative effects of Cd than its lower concentration. Remarkable genotypic variation was found, with more severe effects of both the metals in P792 than Sel 85N. Glomus mosseae attenuated the phytotoxic effects of metals in nodules by decreasing metal uptake, oxidative stress, and by enhancing defense system ultimately leading to better nitrogen-fixing potential of pigeonpea nodules.     

Insulin inhibits glucose production by a direct effect in diabetic depancreatized dogs during euglycemia

In our previous studies in nondiabetic dogs and humans, insulin suppressed glucose production (GP) by both an indirect extrahepatic and a direct hepatic effect. However, insulin had no direct effect on GP in diabetic depancreatized dogs under conditions of moderate hyperglycemia. The present study was designed to investigate whether insulin can inhibit GP by a direct effect in this model under conditions of euglycemia. Depancreatized dogs were made euglycemic (approximately 6 mmol/l), rather than moderately hyperglycemic (approximately 10 mmol/l) as in our previous studies, by basal portal insulin infusion. After approximately 100 min of euglycemia, a hyperinsulinemic euglycemic clamp was performed by giving an additional infusion of insulin either portally (POR) or peripherally at about one-half the rate (1/2 PER) to match the peripheral venous insulin concentrations. The greater hepatic insulin load in POR resulted in greater suppression of GP (from 16.5 +/- 1.8 to 12.2 +/- 1.6 micromol. kg(-1). min(-1)) than 1/2 PER (from 17.8 +/- 1.9 to 15.6 +/- 2.0 micromol. kg(-1). min(-1), P < 0.001 vs. POR), consistent with insulin having a direct hepatic effect in suppressing GP. We conclude that the direct effect of insulin to inhibit GP is present in diabetic depancreatized dogs under conditions of acutely induced euglycemia. These results suggest that, in diabetes, the prevailing glycemic level is a determinant of the balance between insulin's direct and indirect effects on GP.     

Recent Perspectives on Cross Talk Between Cadmium,Zinc, and Arbuscular Mycorrhizal Fungi in Plants

Journal of Plant Growth Regulation - Soils polluted with heavy metals result into various environmental and ecological tribulations like alterations in microbial community, deterioration of soil,...