Back to Search
Start Over
The Importance of Non-Diffusional Factors in Determining Photosynthesis of Two Contrasting Quinoa Ecotypes (Chenopodium quinoa Willd.) Subjected to Salinity Conditions
- Source :
- Plants, Vol 10, Iss 5, p 927 (2021)
- Publication Year :
- 2021
- Publisher :
- MDPI AG, 2021.
-
Abstract
- The broad distribution of quinoa in saline and non-saline environments is reflected in variations in the photosynthesis-associated mechanisms of different ecotypes. The aim of this study was to characterize the photosynthetic response to high salinity (0.4 M NaCl) of two contrasting Chilean genotypes, Amarilla (salt-tolerant, salares ecotype) and Hueque (salt-sensitive, coastal ecotype). Our results show that saline stress induced a significant decrease in the K+/Na+ ratio in roots and an increase in glycine betaine in leaves, particularly in the sensitive genotype (Hueque). Measurement of the photosynthesis-related parameters showed that maximum CO2 assimilation (Amax) in control plants was comparable between genotypes (ca. 9–10 μmol CO2 m−2 s−1). However, salt treatment produced different responses, with Amax values decreasing by 65.1% in the sensitive ecotype and 37.7% in the tolerant one. Although both genotypes maintained mesophyll conductance when stomatal restrictions were removed, the biochemical components of Amarilla were impaired to a lesser extent under salt stress conditions: for example, the maximum rate of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO; Vcmax) was not as affected in Amarilla, revealing that this enzyme has a higher affinity for its substrate in this genotype and, thus, a better carboxylation efficiency. The present results show that the higher salinity tolerance of Amarilla was also due to its ability to control non-diffusional components, indicating its superior photosynthetic capacity compared to Hueque, particularly under salt stress conditions.
Details
- Language :
- English
- ISSN :
- 22237747
- Volume :
- 10
- Issue :
- 5
- Database :
- Directory of Open Access Journals
- Journal :
- Plants
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.0a361be8d0104e8086a56e13850e3cc5
- Document Type :
- article
- Full Text :
- https://doi.org/10.3390/plants10050927