Reference "Mapping of QTLs associated with cytosolic glutamine synthetase and NADH-glutamate synthase in rice (Oryza sativa L.)"

Reference ID

7826

Title

Mapping of QTLs associated with cytosolic glutamine synthetase and NADH-glutamate synthase in rice (Oryza sativa L.)

Source

Journal of experimental botany, 2001, vol. 52, pp. 1209-1217

Authors (7)

Obara-M	Kajiura-M
Fukuta-Y	Yano-M
Hayashi-M	Yamaya-T
Sato-T

Abstract

Ninety-eight backcross inbred lines (BC1F6) developed between Nipponbare, a
japonica rice, and Kasalath, an indica rice were employed to detect putative
quantitative trait loci (QTLs) associated with the contents of cytosolic
glutamine synthetase (GS1; EC 6.3.1.2) and NADH-glutamate synthase (NADH-GOGAT;
EC 1.4.1.14) in leaves. Immunoblotting analyses showed transgressive
segregations toward lower or greater contents of these enzyme proteins in these
backcross inbred lines. Seven chromosomal QTL regions for GS1 protein content
and six for NADH-GOGAT protein content were detected. Some of these QTLs were
located in QTL regions for various biochemical and physiological traits affected
by nitrogen recycling. These findings suggested that the variation in GS1 and
NADH-GOGAT protein contents in this population is related to the changes in the
rate of nitrogen recycling from senescing organs to developing organs, leading
to changes in these physiological traits. Furthermore, a structural gene for GS1
was mapped between two RFLP markers, C560 and C1408, on chromosome 2 and co-
located in the QTL region for one-spikelet weight. A QTL region for NADH-GOGAT
protein content was detected at the position mapped for the NADH-GOGAT
structural gene on chromosome 1. A QTL region for soluble protein content in
developing leaves was also detected in this region. Although fine mapping is
required to identify individual genes in the future, QTL analysis could be a
useful post-genomic tool to study the gene functions for regulation of nitrogen
recycling in rice.