Interactive effect of elevated CO₂ and nitrogen dose reprograms grain ionome and associated gene expression in bread...

Area of Science:

• Agricultural Science
• Plant Physiology
• Genetics

Background:

• Elevated CO2 (EC) impacts crop physiology, often reducing grain nitrogen and protein content.
• Understanding CO2 x Nitrogen (N) interactions on wheat grain ionome and gene expression is crucial for food security.

Purpose of the Study:

• To investigate the interactive effects of EC and N levels on wheat grain yield, protein, ionome, and gene expression.
• To elucidate the mechanisms behind altered grain composition under future climate conditions.

Main Methods:

• Three bread wheat genotypes were grown under controlled ambient CO2 (AC) and EC conditions with low (LN) and optimum N (ON) treatments.
• Measurements included grain yield, protein, ionome (N, P, K, Ca, Fe, Na), tissue nitrate, and expression of genes TaNAM-B1 and TaYSL6.

Main Results:

• EC generally decreased grain N, P, K, Ca, and Fe, while increasing grain Na. Specific genotypes showed varied responses in nitrate accumulation.
• Gene expression of TaNAM-B1 and TaYSL6, involved in nutrient remobilization, was significantly affected by EC and N levels, particularly in genotype BT. Schomburgk (BTS).
• Lowered expression of these genes under EC conditions correlated with altered grain ionome, suggesting N-dependent transcriptional reprogramming.

Conclusions:

• CO2 and N interactions significantly influence wheat grain composition and nutrient profiles.
• Altered expression of TaNAM-B1 and TaYSL6 under EC contributes to changes in grain ionome, highlighting potential impacts on wheat quality and nutritional value.
• Findings suggest a need for breeding strategies to mitigate negative effects of EC on wheat nutritional quality.