Dynamics of photosynthetic induction and relaxation within the canopy of rice and two wild relatives

We characterized non-steady state photosynthesis in an elite rice cultivar and single accessions of its two closest wild relatives and ancestors. The two wild accessions can adjust more rapidly and assimilate more CO2 during transitions from shade to full sunlight. This suggests considerable breeding potential in using this and broader biodiversity in improving rice productivity. AbstractWild rice species are a source of genetic material for improving cultivated rice (Oryza sativa) and a means to understand its evolutionary history. Renewed interest in non-steady-state photosynthesis in crops has taken place due its potential in improving sustainable productivity. Variation was characterized for photosynthetic induction and relaxation at two leaf canopy levels in three rice species. The wild rice accessions had 16% –40% higher rates of leaf CO2 uptake (A) during photosynthetic induction relative to theO.  sativa accession. However,O.  sativa had an overall higher photosynthetic capacity when compared to accessions of its wild progenitors. Additionally,O.  sativa had a faster stomatal closing response, resulting in higher intrinsic water-use efficiency during high-to-low light transitions. Leaf position in the canopy had a significant effect on non-steady-state photosynthesis, but not steady-state photosynthesis. The results show potential to utilize wild material to refine plant models and improve non-steady-state photosynthesis in cultivated rice for increased productiv...

Source: Food and Energy Security - May 5, 2021 Category: Food Science Authors: Liana G. Acevedo ‐Siaca, Jacqueline Dionora, Rebecca Laza, William Paul Quick, Stephen P. Long Tags: ORIGINAL RESEARCH Source Type: research