Rapid Effect of Nitrogen Supply for Soybean at the Beginning Flowering Stage on Biomass and Sucrose Metabolism

Hongli Zhou,Bo Zhang,Qiang Zhao,Wei Zhang,Xingdong Yao,Futi Xie

doi:10.1038/s41598-019-52043-6

Hongli Zhou, Bo Zhang + Show 4 more

Open Access

https://doi.org/10.1038/s41598-019-52043-6

Copy DOI

Abstract

Nitrogen application at the beginning flowering stage (R1 stage) increased the soybean grain yield, however, the rapid effect of enriched nitrogen at R1 growth stage on soybean dry matter accumulation and sugar metabolism is still unclear. Continuous high nitrogen (CHN), Continuous low nitrogen (CLN), Enriched nitrogen supply at R1 stage (ENS) treatments were applied on two soybean cultivars (Liaodou11, Liaodou14), to investigate the effect of enriched nitrogen on plant biomass accumulation and sucrose metabolism. After 12 h of ENS treatment, the root/shoot rate of both cultivars were lower than that of CLN, but at 24 h it was no significant difference between ENS and CLN. Enriched N at R1 stage, soybean kept a balance of sucrose synthesis and decomposition in leaf by affecting sucrose synthetase (SS) and sucrose phosphate synthase (SPS) activities. Under N limitation condition the plant dry matter accumulation supported root growth priority. Enriched N at R1 stage resulted in the rapid shoot biomass accumulation. In high yield cultivar, the shoot growth was priority to root growth, the common yield cultivar was on the contrary. Our result suggest that enrich N at R1 stage resulted in the accumulation of biomass in shoot rapidly.

Highlights

Nitrogen is an essential element for soybean (Glycine max L.)[1,2,3,4]
At the early growth stage of sugar beet, nitrogen decreased the activities of sucrose synthase and sucrose phosphate synthase, high nitrogen was not benefit for sugar accumulation[25,26]
As the plant grew under a prolonged N limitation condition, the carbon requirement for organs was decreased, under the high N condition, plant required more carbon for nitrogen metbolism for plant growth[7]

Summary

Result

Response of dry mass to enriched N application at R1 stage. Under CHN treatment, the shoot dry mass of CV.L11 was increased significantly from 0 h to 12 h, while high yield CV.L14 was increased significantly from 0 h to 6 h (P < 0.05) (Fig. 1A). The root/shoot ratio of high yield CV.L14 under CHN, CLN and ENS treatments were always lower than that of CV.L11 (Fig. 2A,B). The SPS activity in the high yield CV.L14 root of ENS treatment was significantly lower than those of CHN and CLN treatments (P < 0.05) (Fig. 6D). After 6 h and 12 h, there were no significant differences in the GmSPS expression of 2 cultivars among CHN, CLN and ENS treatments (Fig. 7E,F). The GmSPS expression in the high yield CV.L14 leaf of ENS treatment was significantly higher than those of CHN and CLN treatments (P < 0.05) (Fig. 7F). After 6 h, 12 h and 24 h, there were no significant differences of GmSPS expression among CHN, CLN and ENS treatments in the root of both cultivars (Fig. 8E,F)

Discussion

Findings

Materials and Methods