Maintaining higher leaf photosynthesis after heading stage could promote biomass accumulation in rice

• Published in: Scientific reports Vol. 11; no. 1; pp. 7579 - 11
• Main Authors: Honda, Sotaro, Ohkubo, Satoshi, San, Nan Su, Nakkasame, Anothai, Tomisawa, Kazuki, Katsura, Keisuke, Ookawa, Taiichiro, Nagano, Atsushi J., Adachi, Shunsuke
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 07.04.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/449; 631/449/1734; 631/449/1870; Biomass; Carbon dioxide; Crop Production; Crops; Cultivars; Genome, Plant; Growing season; Growth rate; Growth stage; Humanities and Social Sciences; Inbreeding; Leaves; multidisciplinary; Oryza - genetics; Oryza - growth & development; Oryza - metabolism; Oryza sativa; Photosynthesis; Plant Leaves - growth & development; Plant Leaves - metabolism; Rice; Science; Science (multidisciplinary); Seasons; Species Specificity
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-86983-9

Leaf photosynthetic rate changes across the growing season as crop plants age. Most studies of leaf photosynthesis focus on a specific growth stage, leaving the question of which pattern of photosynthetic dynamics maximizes crop productivity unanswered. Here we obtained high-frequency data of canopy leaf CO 2 assimilation rate ( A ) of two elite rice ( Oryza sativa ) cultivars and 76 inbred lines across the whole growing season. The integrated A value after heading was positively associated with crop growth rate (CGR) from heading to harvest, but that before heading was not. A curve-smoothing analysis of A after heading showed that accumulated A at > 80% of its maximum ( A 80 ) was positively correlated with CGR in analyses of all lines mixed and of lines grouped by genetic background, while the maximum A and accumulated A at ≤ 80% were less strongly correlated with CGR. We also found a genomic region (~ 12.2 Mb) that may enhance both A 80 and aboveground biomass at harvest. We propose that maintaining a high A after heading, rather than having high maximum A , is a potential target for enhancing rice biomass accumulation.