Jilin Province Engineering Laboratory of Plant Genetic Improvement, College of Plant Science, Jilin University, Changchun, China.
Plant Signal Behav. 2021 Jul 3;16(7):1916211. doi: 10.1080/15592324.2021.1916211. Epub 2021 May 26.
Aluminum (Al) toxicity in acidic soils severely reduces crop production worldwide. Sorghum ( L.) is an important agricultural crop widely grown in tropical and subtropical regions, where Al toxicity is prevalent. ATP-binding cassette (ABC) transporters play key roles in the development of plants and include the member sensitive to aluminum rhizotoxicity 1 (STAR1), which is reported to be associated with Al tolerance in a few plant species. However, a STAR1 homolog has not been characterized in sorghum with respect to Al tolerance. Here, we identified and characterized a gene in sweet sorghum encoding the nucleotide-binding domain of a bacterial-type ABC transporter. The transcriptional expression of is induced by Al in a time- and dosage-dependent manner in root, especially in root tip, which is the key site of Al toxicity in plants. The typical Al-associated transcription factor SbSTOP1 showed transcriptional regulation of . SbSTAR1 was present at both the cytoplasm and nuclei. Overexpression of significantly enhanced the Al tolerance of transgenic plants, which possibly via regulating the hemicellulose content in root cell wall. This study provides the first ABC protein in sorghum implicated in Al tolerance, suggesting the existence of a SbSTAR1-mediated Al tolerance mechanism in sorghum.
在酸性土壤中，铝（Al）毒性会严重降低全球作物的产量。高粱（Sorghum）是一种重要的农业作物，广泛生长在热带和亚热带地区，这些地区普遍存在铝毒性。ATP 结合盒（ABC）转运蛋白在植物的发育中起着关键作用，其中包括对铝根毒性敏感的成员 1（STAR1），据报道，该成员与一些植物物种的耐铝性有关。然而，在高粱中，尚未对耐铝性的 STAR1 同源物进行表征。在这里，我们鉴定并表征了甜高粱中的一个基因，该基因编码细菌型 ABC 转运蛋白的核苷酸结合域。在根中，特别是在根尖， 基因的转录表达随 Al 的时间和剂量呈依赖性诱导，根尖是植物中 Al 毒性的关键部位。典型的 Al 相关转录因子 SbSTOP1 对 进行转录调控。SbSTAR1 存在于细胞质和细胞核中。过表达 显著增强了转基因植物的耐铝性，这可能是通过调节根细胞壁中半纤维素的含量来实现的。本研究首次在高粱中发现了一种与 Al 耐受性相关的 ABC 蛋白，表明在高粱中存在 SbSTAR1 介导的 Al 耐受性机制。
