OsYSL13 transporter may play a role in Mn homeostasis in rice (Oryza sativa L.)

Iron (Fe) is an essential element for almost all living organisms. In plants, it is a key player in electron transport in both photosynthesis and respiration. Rice ( Oryza sativa L.) is a crop that feeds half of the world’s population. However, rice grains have low Fe concentrations, making populations that base their diet on this crop prone to Fe deficiency. Nutritional Fe deficiency can be addressed by biofortification. To achieve this goal, however, it is necessary to understand plants’ Fe homeostasis mechanisms. Here we evaluate the physiological consequences of loss of OsYSL13 gene in Fe homeostasis and possible alterations in manganese (Mn) homeostasis. We found that leaves of osysl13 mutant plants have lower concentrations of Fe and Mn when extra Mn is added to the soil, compared to wild-type (WT) plants. Mutant osysl13 plants less compared to WT not only in control, but also under Mn deficiency, with decreased shoot biomass accumulation and root length, as well as increased root diameter, suggesting that OsYSL13 has a function in Mn homeostasis. Interestingly, we observed that osysl13 mutant plants accumulate higher H 2 O 2 levels in their leaves, causing visible damages. Mn concentration was also higher in osysl13 leaves compared to WT. Our data suggest that OsYSL13 might be relevant in Mn homeostasis, especially in older leaves facing excessive Mn detoxification,