biostudies-literatureUnknown13Li RJNod factors secreted by nitrogen-fixing rhizobia are lipo-chitooligosaccharidic signals required for establishment of the nodule symbiosis with legumes. In <i>Medicago truncatula</i>, the Nod factor hydrolase 1 (MtNFH1) was found to cleave Nod factors of <i>Sinorhizobium meliloti</i>. Here, we report that the class V chitinase MtCHIT5b of <i>M. truncatula</i> expressed in <i>Escherichia coli</i> can release lipodisaccharides from Nod factors. Analysis of <i>M. truncatula</i> mutant plants indicated that MtCHIT5b, together with MtNFH1, degrades <i>S. meliloti</i> Nod factors in the rhizosphere. <i>MtCHIT5b</i> expression was induced by treatment of roots with purified Nod factors or inoculation with rhizobia. MtCHIT5b with a fluorescent tag was detected in the infection pocket of root hairs. Nodulation of a <i>MtCHIT5b</i> knockout mutant was not significantly altered whereas overexpression of <i>MtCHIT5b</i> resulted in fewer nodules. Reduced nodulation was observed when <i>MtCHIT5b</i> and <i>MtNFH1</i> were simultaneously silenced in RNA interference experiments. Overall, this study shows that nodule formation of <i>M. truncatula</i> is regulated by a second Nod factor cleaving hydrolase in addition to MtNFH1.Frontiers in plant science1034230https://www.ebi.ac.uk/biostudies/studies/S-EPMC9712974biostudies-literatureThe <i>Medicago truncatula</i> hydrolase MtCHIT5b degrades Nod factors of <i>Sinorhizobium meliloti</i> and cooperates with MtNFH1 to regulate the nodule symbiosis.PMC9712974Mysore KSXie ZPWen JLi RJStaehelin CZhang CXWang YHFan SYfalseThe <i>Medicago truncatula</i> hydrolase MtCHIT5b degrades Nod factors of <i>Sinorhizobium meliloti</i> and cooperates with MtNFH1 to regulate the nodule symbiosis.Nod factors secreted by nitrogen-fixing rhizobia are lipo-chitooligosaccharidic signals required for establishment of the nodule symbiosis with legumes. In <i>Medicago truncatula</i>, the Nod factor hydrolase 1 (MtNFH1) was found to cleave Nod factors of <i>Sinorhizobium meliloti</i>. Here, we report that the class V chitinase MtCHIT5b of <i>M. truncatula</i> expressed in <i>Escherichia coli</i> can release lipodisaccharides from Nod factors. Analysis of <i>M. truncatula</i> mutant plants indicated that MtCHIT5b, together with MtNFH1, degrades <i>S. meliloti</i> Nod factors in the rhizosphere. <i>MtCHIT5b</i> expression was induced by treatment of roots with purified Nod factors or inoculation with rhizobia. MtCHIT5b with a fluorescent tag was detected in the infection pocket of root hairs. Nodulation of a <i>MtCHIT5b</i> knockout mutant was not significantly altered whereas overexpression of <i>MtCHIT5b</i> resulted in fewer nodules. Reduced nodulation was observed when <i>MtCHIT5b</i> and <i>MtNFH1</i> were simultaneously silenced in RNA interference experiments. Overall, this study shows that nodule formation of <i>M. truncatula</i> is regulated by a second Nod factor cleaving hydrolase in addition to MtNFH1.2022-01-01T00:00:00Z20222025-05-29T21:51:03.961Z2025-05-29T21:51:03.961ZS-EPMC97129743646627110.3389/fpls.2022.1034230