Sulfur deficiency had different effects on Medicago truncatula ecotypes A17 and R108 in terms of growth, root morphology and nutrient contents

ABSTRACT

Medicago truncatula is a model legume species with a diverse genetic diversity. To explore whether different ecotypes of Medicago truncatula differ in their response to sulfur deficiency, the effects of sulfur (S) deficiency on the two ecotypes (A17 and R108) were investigated. Sulfur deficiency stimulated lateral root initiation in the root apical region of both ecotypes, but did not affect their overall biomass. The S deficiency-induced changes in root morphology were more distinct in R108 plants than in A17 plants. Exposure to S deficiency led to a greater reduction in leaves and roots of R108 than those of A17 plants. The concentrations of majority of other mineral nutrients were increased in A17 plants, while they were mainly reduced in R108 plants under S-deficient conditions. A greater reduction in R108 plants than in A17 plants was found under S-deficient conditions. An accumulation of anthocyanin in R108 was observed under S-deficient conditions. These results indicate that the ecotype R108 appears more sensitive to S deficiency than the ecotype A17.

KEYWORDS:

• Sulfur deficiency
• Medicago truncatula
• ecotype A17 and R108
• anthocyanin
• root morphology

Funding

This work was supported by Natural Science Foundation of China (31272234) and the National Basic Research Program of China (2015CB150800).