ABSTRACT
Aluminum (Al) is the major limiting factor affecting plant productivity in acidic soils. Al3+ ions exhibit increased solubility at a pH below 5, leading to plant root tip toxicity. Alternatively, plants can perceive very low concentrations of Al3+, and Al triggers downstream signaling even at pH 5.7 without causing Al toxicity. The ALUMINUM-ACTIVATED-MALATE-TRANSPORTER (ALMT) family members act as anion channels, with some regulating the secretion of malate from root apices to chelate Al, which is a crucial mechanism for plant Al resistance. To date, the role of the ALMT gene family within the legume Medicago species has not been fully characterized. In this study, we investigated the ALMT gene family in M. sativa and M. truncatula and identified 68 MsALMTs and 18 MtALMTs, respectively. Phylogenetic analysis classified these genes into five clades, and synteny analysis uncovered genuine paralogs and orthologs. The real-time quantitative reverse transcription PCR (qRT-PCR) analysis revealed that MtALMT8, MtALMT9, and MtALMT15 in clade 2-2b are expressed in both roots and root nodules, and MtALMT8 and MtALMT9 are significantly upregulated by Al in root tips. We also observed that MtALMT8 and MtALMT9 can partially restore the Al sensitivity of Atalmt1 in Arabidopsis. Moreover, transcriptome analysis examined the expression patterns of these genes in M. sativa in response to Al at both pH 5.7 and pH 4.6, as well as to protons, and found that Al and protons can independently induce some Al-resistance genes. Overall, our findings indicate that MtALMT8 and MtALMT9 may play a role in Al resistance, and highlight the resemblance between the ALMT genes in Medicago species and those in Arabidopsis.
Subject(s)
Aluminum , Gene Expression Profiling , Phylogeny , Plant Proteins , Aluminum/toxicity , Plant Proteins/genetics , Plant Proteins/metabolism , Gene Expression Regulation, Plant/drug effects , Multigene Family , Medicago truncatula/genetics , Medicago truncatula/drug effects , Medicago truncatula/metabolism , Medicago sativa/genetics , Medicago sativa/drug effects , Medicago sativa/physiology , Plant Roots/genetics , Plant Roots/drug effects , Plant Roots/metabolism , Genome, Plant , Organic Anion Transporters/genetics , Organic Anion Transporters/metabolism , Medicago/genetics , Medicago/physiologyABSTRACT
Lupus miliaris disseminatus faciei (LMDF) is a rare chronic inflammatory and granulomatous skin disease characterized by reddish-brown papules and nodules on the central face. Although this disease can spontaneously resolve, disfiguring scars can often remain. This disease responds poorly to general treatments. Except for systemic hormones, the efficacy of other drugs is unclear. There are few reports on the use of laser treatment for LMDF. Here, we report a case of LMDF that was successfully treated with a 595 nm pulsed-dye laser combined with glucocorticoids and isotretinoin. The treatment outcome shows less scar formation and fewer side effects when this regimen was employed.
