FIGURE 1 Chromosomal locations of the enzyme genes in the
AsA-GSH cycle and nitrogen metabolism in rice and similar genes in other
species. (a), (b), (c), (d), and (e) represent the chromosomes of rice,Arabidopsis thaliana ,Hordeum vulgare , Zea
mays , and Sorghum bicolor ,
respectively.
3.3| Exon-intron structure of enzyme genes in the AsA-GSH
cycle and nitrogen metabolism in rice and similar genes in other
species
(Figure 2a–e) show the exon-intron structure and the ratio of intron
phases 0, 1, and 2 to all introns of the enzyme genes in the AsA-GSH
cycle and nitrogen metabolism in rice, and similar genes inArabidopsis thaliana , Hordeum vulgare , Zea mays ,
and Sorghum bicolor . The exon numbers of ATGR andATGR1 were 10 and 16, respectively; and the GR gene has 10 exons
in rice, Hordeum vulgare , Zea mays , and Sorghum
bicolor . The exon number of the GPX genes was the same in all species,
with six exons. Except for ATNIA1 and ATNIA2 , there were
four and three exons, and two and three exons in Hordeum vulgareNR genes; and four exons in rice, Zea mays , and Sorghum
bicolor NR genes, respectively. The GS gene exon number was 11 in rice.
Further, Arabidopsis thaliana GS genes had 9, 12, 9, and 10
exons; Hordeum vulgare GS genes had 10 and 11 exons; Zea
mays GS genes had 10, 10, and 11 exons; and Sorghum bicolor GS
gene had 10 exons. There were 22 exons of the GOGAT gene in all species,
except ATGLT1 , which had 20 exons. From the intron phase results
of (Figure 2f–j), intron phase 0 of each species was found to account
for 56%-60%, which served as the largest proportion. Intron phase 1
was 16%, 13%, 19%, 13%, and 16% in rice, Arabidopsis
thaliana , Hordeum vulgare , Zea mays , and Sorghum
bicolor , respectively; and the proportion of intron phase 2 was
23%-30% in each species. Based on an analysis of the intron phase of
each species, the intron phases were found to account for 0, 1, and 2 of
all introns in rice, Arabidopsis thaliana , Hordeum
vulgare , Zea mays , and Sorghum bicolor have similar
results.