Distribution and Mobilization of Sulfur during Soybean Reproduction

Abstract

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Amino Acid Balance is Affected by Protein Concentration in Soybean

“…The abundant RuBisCO enzyme is enriched in cysteine + methionine and threonine that increased under shade conditions here; however, not all amino acids that were found to increase in relative abundance under shade are enriched in RuBisCO (Schmitz-Linneweber et al, 2001). Naeve and Shibles (2005) demonstrated the dependence of seed protein on mobilized S from vegetative tissues. Together, this supports a possible role for vegetative reserves to support protein quality through enhancing the relative amounts of the limiting amino acids, which may be less C-dependent.…”

“…Shade, however, tended to increase the relative abundance of lysine, methionine, cysteine, threonine, and histidine to a greater extent than expected based on these regressions. Naeve and Shibles (2005) demonstrated the dependence of seed protein on mobilized S from vegetative tissues. This lack of supplied C separates whole-plant source-sink conditions imposed by the shade treatment from the other treatments that resulted in higher protein concentration, open environment, and pod removal.…”

Is the remobilization of S and N reserves for seed filling of winter oilseed rape modulated by sulphate restrictions occurring at different growth stages?

“…Sunarpi and Anderson (1998) described S redistribution in S-deficient vegetative soybean (with an 35 S pulse–chase labelling method) and reported that ∼25% of the mobilized S was recycled as 34 SO 4 2− via the root and the largest newly expanded leaf, which acts as an intermediary in the transport of S from the root to the youngest expanding leaves. S mobilization in suboptimal conditions of S fertilization was also examined in reproductive soybean (Sunarpi and Anderson, 1997; Naeve and Shibles, 2005). These authors reported that soybean leaves did not act as large reservoirs for S in conditions of suboptimal S fertilization.…”

“…These authors reported that soybean leaves did not act as large reservoirs for S in conditions of suboptimal S fertilization. Nevertheless, under SO 4 2− -sufficient conditions, it was shown that leaves of soybean supplied the seed with 20% of its total S requirement (Naeve and Shibles, 2005). Therefore, in soybean, the amount of S mobilized from leaves at the reproductive stage appears to be reliant on the amount previously stored in roots and leaves.…”

Transcripts of sulphur metabolic genes are co-ordinately regulated in developing seeds of common bean lacking phaseolin and major lectins

“…Assimilation of transported S -methyl-Met requires homocysteine as an acceptor of the S -methyl group. Under sulphur-sufficient conditions, soybean seeds do accumulate detectable levels of sulphate throughout development (Naeve and Shibles, 2005). Recent functional genomic studies have highlighted the occurrence of complete pathways of sulphate assimilation and de novo Cys and Met biosynthesis in developing seed, both in soybean and common bean (Yi et al ., 2010; Yin et al ., 2011).…”