39 research outputs found
Role of methionine sulfoxide reductase in seed longevity: from theory to practice
International audienc
Role of thioredoxins in the differentiation of Sinorhizobium meliloti during symbiosis with Medicago truncatula
Deciphering the nitrate signaling pathway leading to a reduction of primary root growth in Medicago truncatula
In the model legume Medicago truncatula, nitrate has been shown to inhibit primary root growth through the reduction of root cell elongation. Nitrate, as an essential nutrient, also acts as a signal molecule that is sensed and transduced through a nitrate transporter MtNPF6.8, with RNAi mutants deficient in MtNPF6.8 being insensitive to nitrate [1, 2]. We tested here whether reactive oxygen species (ROS) could be downstream mediators of the nitrate signal since ROS are able to transduce ABA signal in other contexts and also govern the primary root growth. Thus, we analyzed the distribution of ROS (H2O2, O2•−, •OH) and peroxidase activity all along the primary root of seedlings sensitive or insensitive to nitrate using different genotypes of M. truncatula, three wild types and a npf6.8RNAi mutant grown with or without nitrate, to determine whether nitrate modifies ROS and peroxidase patterns. We found that nitrate modified the morphology of the root tip, induced an increase in H2O2, and a decrease in O2•− and •OH in seedlings sensitive to nitrate (R108, A17, and DZA315-16), but not in seedlings insensitive to nitrate (npf6.8RNAi mutant). These results suggest that ROS and peroxidases are downstream mediators in the nitrate signaling pathway. The origin of the change in ROS accumulation in response to nitrate was further investigated following the activity of major enzymes (peroxidase, SOD, Nox) able to interfere with ROS accumulation
Evidence for the participation of the methionine sulfoxide reductase repair system in plant seed longevity
Functional characterization of the Medicago truncatula dual affinity nitrate transporter MtNRT1.3 and regulation of gene expression
Characterization of Medicago truncatula nitrate transporter MtNRT1.3 (MtNPF6.8): role in the nitrate signal perception
Implication des méthionines sulfoxide réductases dans la longévité des graines
International audienc