Impact of elevated atmospheric CO2 on aleurone cells and starch granule morphology in domesticated and wild rices. (January 2022)

• Record Type: Journal Article
• Authors: Rahman, Sayedur; Copeland, Les; Atwell, Brian J.; Roberts, Thomas H.
• Is Part Of: Journal of cereal science. Volume 103(2022)
• Publication Date: 2022-01
• Subjects: Aleurone -- Elevated CO2 -- Oryza meridionalis -- Oryza australiensis -- Starch granule; Grain -- Periodicals; Cereal products -- Periodicals; Céréales -- Périodiques; Produits céréaliers -- Périodiques; Cereal products; Grain; Periodicals; 664.705
• DOI: 10.1016/j.jcs.2021.103389
• Languages: English
• ISSNs: 0733-5210

Abstract

Abstract: Wild rice species represent valuable germplasm for breeding of elite genotypes with enhanced resistance to biotic and abiotic stresses. However, differences in endosperm morphology between wild and cultivated rice, and how these are affected by enhanced levels of atmospheric CO2 (eCO2 ) predicted for later this century, are largely unknown. Accessions of native rice species from northern Australia, Oryza australiensis and O. meridionalis, and a local cultivar, O. sativa cv. Doongara, were grown to maturity in glasshouses at ambient (aCO2, 400 ppm) and eCO2 (700 ppm). Endosperm morphology was studied from transverse sections of mature grains using scanning electron microscopy. Aleurone cell length and width were higher in eCO2 than in aCO2 in the O. meridionalis accession Howard Springs, but lower in Doongara. The average starch granule size in Doongara was greater than in the wild genotypes in both CO2 treatments. The area and length of the starch granule images were larger in eCO2 than in aCO2 in the O. meridionalis accession Cape York but smaller in Doongara. Responses of rice endosperm morphology to eCO2 were dependent on genotype. We conclude that endosperm morphology responds differentially to eCO2, both between and within rice species. Contrasts in these responses can be exploited by breeders. Graphical abstract: Image 1 Highlights: Australian wild Oryza species and commercial rice were grown at 400 and 700 ppm CO2 . SEM imaging revealed the morphology of aleurone cells and starch granules in grains. Aleurone cells were larger after CO2 enrichment in one O. meridionalis accession. Starch granules were larger after CO2 enrichment in a second accession. Genotype × CO2 interactions (typically p < 0.0001) were seen in endosperm morphology.