The ALMT Gene Family Performs Multiple Functions in Plants

Abstract

Abstract:The aluminium activated malate transporter (ALMT) gene family is named after the first member of the family identified in wheat (Triticum aestivum L.). The product of this gene controls resistance to aluminium (Al) toxicity. ALMT genes encode transmembrane proteins that function as anion channels and perform multiple functions involving the transport of organic anions (e.g., carboxylates) and inorganic anions in cells. They share a PF11744 domain and are classified in the Fusaric acid resistance protein-like superfamily, CL0307. The proteins typically have five to seven transmembrane regions in the N-terminal half and a long hydrophillic C-terminal tail but predictions of secondary structure vary. Although widely spread in plants, relatively little information is available on the roles performed by other members of this family. In this review, we summarized functions of ALMT gene families, including Al resistance, stomatal function, mineral nutrition, microbe interactions, fruit acidity, light response and seed development.

Genome-Wide Identification of Aluminum-Activated Malate Transporter (ALMT) Gene Family in Rubber Trees (Hevea brasiliensis) Highlights Their Involvement in Aluminum Detoxification

“…The aluminum-activated malate transporter (ALMT) gene encodes anion transporter/channel and it can transport organic and inorganic anions through the tonoplast and plasma membrane in cells [15,17]. Genes encoding malate transporters have been found in many plant species, such as Arabidopsis (AtALMT1), rape (BnALMT1, BnALMT2), rye (ScALMT1), and soybean (GmALMT1) [18][19][20][21].…”

“…Even though the rubber tree is an Al tolerant plant, its Al tolerant mechanism has not been studied. It was reported that ALMTs played vital roles in Al detoxification of many plants [15,17]. Therefore, identification of ALMTs from rubber tree genome will be helpful for the comprehensive understanding of the Al tolerant mechanism and for the development of Al-resistant cultivars.…”

Alleviating aluminum toxicity in plants: Implications of reactive oxygen species signaling and crosstalk with other signaling pathways

“…Two transporter gene families, ALMT (Aluminium Activated Malate Transporter) and MATE, have been identified in plants as responsible for the exudation of organic acids, hence conferring Al tolerance (Magalhaes et al, 2007;Sasaki et al, 2004). The ALMT family comprises of functionally diverse but structurally similar type of ion channels; they are found ubiquitously in all plant species, expressed throughout different tissues and located in either plasma membrane or tonoplast (Liu & Zhou, 2018). The ALMT family is a multigene family, that consists of fourteen members in Arabidopsis (Sharma, Dreyer, et al, 2016) and nine members in rice (Heng et al, 2018).…”

Strategies of tolerance reflected in two North American maple genomes

“…Its role in regards to aluminum is unknown, though it is responsive to cold and stress-related hormones (Kidokoro et al, 2017), and CAMTA2 is a positive regulator of ALMT1 (Tokizawa et al, 2015). ALMTs are anion channels involved in a wide variety of processes, and although ALMT1 is known to be expressed in roots in response to aluminum (Hoekenga et al, 2006), most ALMT are not thought to be involved in aluminum tolerance (Liu & Zhou, 2018). Recent characterization of ALMT10, upregulated in SpAl in a pattern similar to metallothionein, proposes involvement in homeostasis of Clefflux and NO3assimilation, induced by water deficit (Racero & J, 2020).…”