Nitrogen metabolism in sorghum under salinity and silicon treatments in Brazil

Abstract

The objective of the present research was to study nitrogen metabolism in sorghum plants subjected to salt stress and silicon concentration. The experiment was conducted at the Amazon Federal Rural University, Capitão Poço Decentralized Unit for 1 month, in 2013, using the cultivar BR 700 of forage sorghum plants (Sorghum bicolor [Moench.]). The experimental design was completely randomized, in a 5 × 3 factorial arrangement (0, 50, 100, 150 and 200 µM of silicon) and saline concentrations (0, 1.5 and 2.0 M), consisting of 4 replications. Analyses were conducted of amino acids, proteins, free ammonium, nitrate and nitrate reductase. Nitrate content increased in the leaves and root in the treatments 0 and 1.5 µM of Si, but decreased in treatments with the 0.5 and 1.0 µM doses of Si. In leaves and roots, the treatments 1.5 and 2.0 of SC caused reduction and increase, respectively, of ammonium levels. The silicon doses attenuated the negative effects of the treatments on the biochemical compounds caused by higher salt concentrations in sorghum plants.

Salinity reduces nutrients absorption and efficiency of their utilization in cassava plants

“…However, the efficiency in N use was the one that suffered the greatest reduction (-60%). In fact, salinity has been shown to reduce several parameters related to N metabolism in plants, such as NO 3 absorption, free aminoacid, leaf protein, and activity of the enzymes nitrate reductase, glutamine synthase, and glutamate synthetase (SOUZA et al, 2016;KAUSAR et al, 2014;MENG et al, 2016;IQBAL et al, 2015;WANG et al, 2012;DEBOUBA et al, 2006;SILVEIRA et al, 2001), and these reductions have been higher in the varieties more sensitive to salinity (KAUSAR et al, 2014). Thus, given the importance of this nutrient for plant physiology and growth, studies related to N metabolism could also be prioritized in studies of cassava tolerance to salinity.…”