Expression of the Genes OsNRT1.1, OsNRT2.1, OsNRT2.2, and Kinetics of Nitrate Uptake in Genetically Contrasting Rice Varieties

Abstract

Four genetically contrasting rice varieties (IAC-47, Bico Ganga, Arroz de Revenda and Manteiga) according to Random Amplified Polymorphic DNA (RAPD) analysis were assessed regarding expression of the genes OsNRT1.1, OsNRT2.1 and OsNRT2.2 and the nitrate uptake kinetics parameters (K m and V max ). Up to 250-fold increases in the induction of gene expression after nitrate resupply were observed for the high-affinity transporter (OsNRT2.1 and OsNRT2.2). However, no significant variations in V max among the varieties were obtained. The lower value of K m of the IAC-47 cultivar in relation to the Arroz de Revenda variety suggests a greater role of high-affinity transporter genes. These results indicate that closer attention should be paid to the expression levels of these genes in selecting varieties aiming to enhance nitrogen uptake efficiency.

Sensing of Abiotic Stress and Ionic Stress Responses in Plants

“…AtNRT1.1 is involved in both high- and low-affinity uptake of NO 3 − , whereas AtNRT1.2 works in low-affinity uptake [ 107 , 108 ]. In rice, up to 250-fold increases in the induction of gene expression after nitrate resupply were observed for the high-affinity transporters OsNRT2.1 and OsNRT2.2 [ 109 ].…”

Influência Da Granulometria Na Dureza Do Organomineral Granulado

“…Foi verificado aumento na expressão relativa do gene OsNRT1.1 nos tratamentos MLEP50, MLEP60, MLEP80, MLEP90 e MLEP100. Esse aumento pode ter relação com a função do gene, um transportador de dupla afinidade, no reconhecimento e importação de NO 3 -, além do mecanismo de tolerância em situações adversas (HO et al, 2009;ARAÚJO et al, 2015;FANG et al, 2021)…”

Kinetic parameters govern of the uptake of nitrogen forms in ‘Paulsen’ and ‘Magnolia’ grapevine rootstocks

“…Shortly thereafter, there was a decrease in NH 4 + uptake up to 50 h of evaluation for both rootstocks. This could possibly be due to the low induction of proteins that act in NH 4 + transport to the interior of roots This demonstrates the relevance of more spaced solution collections in initial absorption hours of these plants, as well as an evaluation time greater than 5 h, as used for Chinese kale (Song et al, 2016), 8 h for rice (Araújo et al, 2015) and 24 h for corn (Horn et al, 2006). In addition, at the end of the solution sampling, we collected some samples in smaller periods, so that it is possible to visualize with more accuracy the real moment plants reach C min .…”

“…On the other hand, it also allows to identify more demanding plants in N, which may require higher N amounts during its development, which can be made available through N fertilizer applications, in order to supply plant N demand. Kinetic parameters related to absorption of N forms have already been reported for annual species such as rice (Araújo et al, 2015), corn (Horn et al, 2006), barley (Glass et al, 1990) and Chinese kale (Song et al, 2016). However, NO 3 − and NH 4 + absorption rates by grapevine rootstocks roots, such as 'Paulsen 1103' and "Magnolia'', are not sufficiently known.…”