Correlation between AS1 Gene Expression and Seed Protein Contents in Different Soybean (Glycine Max [L.] Merr.) Cultivars

Abstract

In higher plants, asparagine synthetase (AS) plays an important role in regulating the nitrogen sink-source relationship. We studied the expression of AS genes in five Chinese soybean cultivars exhibiting contrasting seed protein contents. We found that only the AS2 but not the AS1 gene was induced by dark treatment. On the other hand, the expression of AS1 in leaves (especially in trifoliate leaves of young seedlings) showed a positive correlation with seed protein contents in the soybean cultivars tested. Therefore, in spite of the fact that the principle transporting compounds in soybean plants for nitrogen acquired via symbiotic fixation are ureides, AS may still play an important role in the process of nitrogen assimilation.

Isolation, cloning, and expression of five genes related to nitrogen metabolism in peach (Prunus persicaL. Batsch)

“…This observation confirmed previous findings in high-protein soybean cultivars, where the level of expression of AS1 appeared higher under high light intensity conditions (Wan et al, 2006). However, these results contradicted other reports in which light was shown to repress genes encoding AS in corn, Arabidopsis, and asparagus (Brouquisse et al, 1992;Davis and King, 1993;Lam et al, 1994).…”

“…The AS gene family is reported to be a small gene family with several members; different members probably play different roles in nitrogen metabolism at different developmental stages or in different tissues. This can be exemplified by the expression of AS2 in the dark in all soybean cultivars tested in a study by Wan et al (2006), who also observed that, unlike AS2, expression of AS1 did not increase in any soybean cultivar kept in the dark for 8 h or 48 h.…”

Soybean seed proteome rebalancing

“…Perhaps in response to the elevated free Asn, the steady-state transcript (RNAseq) level for asparaginase increased 6.5X over the conventional controls. In standard lines the asparaginase level was previously correlated with protein content in standard lines (Wan et al, 2006). Together, these observations suggest there is a correlation of protein increase, whether by genotype selection for higher protein content or by increased abundance of individual proteins within the context of the protein genotype, with changes in free Asn and asparaginase.…”

The pivotal role of glutamate dehydrogenase (GDH) in the mobilization of N and C from storage material to asparagine in germinating seeds of yellow lupine

“…Canas et al (2006) showed that the gene PsAS1 encodes the AS responsible for Asn synthesis during pine germination. Storage protein accumulation in soybean is correlated with expression of the gene AS1 (Wan et al, 2006).…”