Differential Responses of Medicago truncatula NLA Homologs to Nutrient Deficiency and Arbuscular Mycorrhizal Symbiosis

• Published in: Plants (Basel) Vol. 12; no. 24; p. 4129
• Main Authors: Lin, Wei-Yi, Yang, Hsin-Ni, Hsieh, Chen-Yun, Deng, Chen
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11.12.2023; MDPI
• Subjects: Alfalfa; Alternative splicing; arbuscular mycorrhizal fungi; Arbuscular mycorrhizas; Fungi; Gene regulation; Genomes; Homeostasis; Homology; Legumes; Localization; Medicago truncatula; Medicago truncatula: phosphate transporter; Membranes; NITROGEN LIMITATION ADAPTATION; Nutrient deficiency; Nutrient status; Phosphate transporter; Phylogenetics; Plasma; Proteins; Symbiosis; Ubiquitin-protein ligase; Medicago truncatula: phosphate transporter; alternative splicing; arbuscular mycorrhizal fungi; NITROGEN LIMITATION ADAPTATION
• ISSN: 2223-7747; 2223-7747
• DOI: 10.3390/plants12244129

NITROGEN LIMITATION ADAPTATION (NLA), a plasma-membrane-associated ubiquitin E3 ligase, plays a negative role in the control of the phosphate transporter family 1 (PHT1) members in Arabidopsis and rice. There are three NLA homologs in the genome, but it has been unclear whether the function of these homologs is conserved in legumes. Here we investigated the subcellular localization and the responses of s to external phosphate and nitrate status. Similar to AtNLA1, MtNLA1/MtNLA2 was localized in the plasma membrane and nucleus. has three alternative splicing variants, and intriguingly, MtNLA3.1, the dominant variant, was not able to target the plasma membrane, whereas MtNLA3.2 and MtNLA3.3 were capable of associating with the plasma membrane. In contrast with , we found that s were not affected or even upregulated by low-phosphate treatment. We also found that was upregulated by arbuscular mycorrhizal (AM) symbiosis, and overexpressing in roots resulted in a decrease in the transcription levels of , an essential gene for arbuscule development. Taken together, our results highlight the difference between homologs and . Further characterization will be required to reveal the regulation of these genes and their roles in the responses to external nutrient status and AM symbiosis.