Accumulation characteristics and structural properties of starch in different spatial positions of wheat endosperm under nitrogen application

Starch accumulation in wheat endosperm has spatial differences. In this study, the accumulation, granule size distribution, physicochemical properties of starch in different spatial positions in wheat endosperm and response to nitrogen treatment were analysed. Results indicated that the starch content in the inner endosperm was higher than that in the outer endosperm. The total starch and amylose contents in the inner and outer endosperms decreased and increased after nitrogen treatment, respectively. The starch granules that accumulated in the inner endosperm were larger than those in the outer endosperm 10 days after anthesis. The amount of C-type starch granules in the inner endosperm was less than that in the outer endosperm, and nitrogen treatment increased the C-type starch granules in the inner endosperm. After nitrogen treatment, the short chains decreased, whereas the middle and long chains increased in the inner and outer endosperms. Nitrogen treatment also increased the crystal area in the inner and outer endosperms, especially the single helix in the inner endosperm. These conclusions provide new insights into the mechanism of starch accumulation in wheat endosperm and its response to the external environment.

Automated summary

Starch accumulation in wheat endosperm varies spatially, with lower starch content in the outer endosperm compared to the inner endosperm. Nitrogen treatment led to a decrease in total starch and an increase in amylose content in the inner and outer endosperms. Starch granules found in the inner endosperm were larger and had fewer C-type granules, but nitrogen treatment increased C-type granules in the inner endosperm. Additionally, nitrogen treatment resulted in a decrease in short chains and an increase in middle and long chains in both the inner and outer endosperms, along with an increase in crystal area, especially the single helix, in the inner endosperm.