The maize germplasm resources innovation team of the Institute of Resources of Jiangsu Academy of Agricultural Sciences published important progress in the study of carbon and nitrogen balance of corn grains in The plant cell

Recently, the research paper "Nitrogen-dependent binding of the transcription factor PBF1 co" independently completed by the Zhao Han team of the Institute of Resources of our institute ntributes to the balance of protein and carbohydrate storage in maize endosperm was officially published in the internationally renowned academic journal "The plant cell", reporting the important research results
in the study of carbon and nitrogen balance in corn grains.

 

Nitrogen (N) is the mineral nutrient with the greatest demand for plant growth and development, and it is also one of the
key factors to promote crop yield increase.
Maize is an important grain and feed crop and bioenergy crop, which plays an important strategic role in China's food security, and its yield and quality are highly
dependent on the amount of nitrogen fertilizer.
In order to ensure the yield of corn, farmers usually apply a large amount of nitrogen fertilizer, but the quality of corn is not guaranteed, and excessive application of nitrogen fertilizer not only increases production costs, causes waste of resources, but also causes environmental problems
such as eutrophication of water bodies and soil acidification.
Therefore, for the green development of agriculture, studying the mechanism of jade carbon and nitrogen balance and mining important regulatory genes in it are helpful to achieve the goal of weight loss without yield reduction in the process of
maize production.

 

The germplasm resources innovation team found that nitrogen restriction affects the expression
of many key genes for nitrogen and carbon (C) metabolism during the development of corn endosperm.
The study found that nitrogen deficiency significantly affected the starch and protein content of corn kernels, and the expression
of many key genes in the grain nitrogen and carbon (C) metabolic pathways.
The promoter regions of these differentially expressed genes in carbon and nitrogen metabolism are rich in P-box sequences
.
The P-box motif is a binding motif sequence of the specific expression of the transcription factor PBF1 in maize endosperm, indicating that PBF1 may be associated with
the differential expression of these key genes.
The loss of function of this gene changed the accumulation of starch and protein in the endosperm, indicating that PBF1 was involved in grain carbon and nitrogen metabolism
.
Based on qRT-PCR, Western Blot and RNA in situ hybridization of maize endosperm after 15 days of pollination under normal nitrogen and nitrogen deficiency environments, it was found that there was no difference in
PBF1 expression level and expression site in different nitrogen environments.
Interestingly, PBF1 binds to different target genes in different nitrogen environments, especially genes
related to the synthesis and accumulation of carbon and nitrogen compounds.
In a nitrogen-deficient environment, the promoters of some of the zein coding genes were not bound by PBF1, and the transcript levels of these gliadin coding genes were reduced, indicating that PBF1 promotes the accumulation
of zein in the endosperm.
At the same time, the transcription level of sugary1 and starch branchase 2b genes was not significantly upregulated
by PBF1 binding in nitrogen deficiency environment.
PBF1 was also found to inhibit the expression
of sugary1 and starch branchase 2b.
The results showed that in the case of nitrogen deficiency, PBF1 would flow more of the C backbone used to synthesize zein to carbohydrate formation
.
The results of this study provide a theoretical basis
for achieving weight loss without yield reduction in maize production.

 

Dr.
Ning Lihua and Dr.
Wang Yuanzhen, the maize germplasm resource innovation team of the Institute of Resources of our institute, are the first authors of the paper, and researcher Zhao Han is the corresponding author
.
The research was supported
by the National Natural Science Foundation of China, the Jiangsu Agricultural Science and Technology Independent Innovation Fund, and the Jiangsu Key Laboratory of Agricultural Biology Major Independent Research Project.

 

Original link: https://academic.
oup.
com/plcell/advance-article/doi/10.
1093/plcell/koac302/6759374?rss=1