Genome-Wide Identification and Characterization of ABC Transporters in Nine Rosaceae Species Identifying MdABCG28 as a Possible Cytokinin Transporter linked to Dwarfing

Abstract

ATP-binding cassette (ABC) transporters constitute a large, diverse, and ubiquitous superfamily that is involved in a broad range of processes. The completion of genome sequencing provides an opportunity to understand the phylogenetic history of the ABC transporter superfamily among Rosaceae species. This study identified a total of 1323 ABC transporter genes from nine Rosaceae genomes: 191 from Malus domestica, 174 from Pyrus communis, 138 from Prunus persica, 118 from Prunus avium, 141 from Prunus dulcis, 122 from Fragaria vesca, 98 from Rubus occidentalis, 162 from Prunus mume, and 179 from Rosa chinensis. Their chemical characterization, phylogenetic analysis, chromosomal localization, gene structure, gene duplication, and tissue-specific expression were studied. Their subcellular localization, transmembrane structures, and protein motifs were predicted. All the ABC transporter genes were grouped into eight subfamilies on the basis of their phylogenetic relationships and structural features. Furthermore, cis-element and expression analysis of 10 potential phytohormone transporters in MdABCG subfamily genes were also performed. Loss of the W-box in the promoter region of MdABCG28 was found to reduce the gene expression level and was linked to the dwarfing phenotype in apple rootstocks. MdABCG28 overexpression promoted shoot growth of atabcg14 mutants in Arabidopsis.

Genome-Wide Identification of Soybean ABC Transporters Relate to Aluminum Toxicity

“…In plants, ABC transporters have many types, complex structures, and diverse functions, which are involved in all the life activities of plants. In previous studies, the ABC transporter gene family has been systematically analyzed in multiple plants and has been found to play vital roles in the growth, development, and response to abiotic and biotic stresses of plants [ 6 , 40 , 41 , 42 , 43 ]. Here, we performed a comprehensive analysis of the GmABC genes and provided a reference for further exploration in soybean.…”

“…In our study, a total of 255 putative GmABC genes were identified in soybean via genome-wide analysis, accounting for 0.296% of the total 86,247 annotated genes of its reference sequence ( Table S1 ). Reports have shown the existence of 154 SlABCs [ 6 ], 121 OsABCs [ 41 ], 120 AtABCs [ 41 ], 130 ZmABCs [ 42 ], 121 StABCs (unpublished), and 191 MdABCs [ 40 ]. Genome size varies in different plants (i.e., G. max [1.1 Gb], S. lycopersicum [942 Mb], O. sativa [466 Mb], A. thaliana [125 Mb], Z. mays [2.3 Gb], S. tuberosum [844 Mb], M. domestica [742 Mb]), indicating that the number of ABC transporters is inconsistent with their genome sizes.…”

Genome-Wide Identification of Brassinosteroid Signaling Downstream Genes in Nine Rosaceae Species and Analyses of Their Roles in Stem Growth and Stress Response in Apple

“…A total of 196 BR signaling downstream genes were identified: 15-23 from nine Rosaceae species ( Figure 1A), including 3-8 BZR1/2s and 1-3 other genes. All proteins, except for several SPYs, AtGSR1, and FvGSR1-3, shared instability indices above 40 ( Figure 1B and Supplementary Table S4) and were unstable according to the published criteria (Feng et al, 2019). Most proteins did not contain transmembrane structures, except for MdBZR8, PcBZR3, RcBZR4, and so on ( Figure 1C and Supplementary Figure S2).…”

The Hulks and the Deadpools of the Cytokinin Universe: A Dual Strategy for Cytokinin Production, Translocation, and Signal Transduction

“…Several members of the ATP-binding cassette transporter subfamily G , namely Arabidopsis At ABCG14 [ 301 , 302 ], rice Os ABCG18 [ 303 ], and apple tree Md ABCG28 and 70 [ 304 ], were recently shown to transport CKs. The first indicia was co-expression of AtABC G14 with AtIPTs and induction of its expression upon CK treatment [ 302 ].…”

“…The knockout mutant phenotypes resembled other CK-deficient mutants [ 301 , 302 , 303 ]. Similarly, the expression of MdABC G28 was decreased in a dwarf line of apple tree [ 304 ]. The dwarf phenotype of shoots could be rescued by application of t Z but not iP [ 302 , 303 ], while root elongation was less sensitive to t Z application in the mutants than in WT plants [ 301 ].…”