CAJ | 학술논문

植物 TRK-HKT 家族基因广泛介导植物 Na+/K+运输,参与植物耐逆境胁迫调控。本研究以6个大豆钾利用效率差异品种为材料,利用 in silico 技术克隆到4个大豆 TRK-HKT 家族成员(GmHKT1；1、GmHKT1；2、GmHKT1；3和 GmHKT1；4),采用 qRT-PCR 技术解析这些基因在低钾及逆境胁迫下的表达机制。结果表明, GmHKT1；2在大豆幼苗根中对低钾胁迫的响应明显高于其他3个基因,且钾高效大豆品种这种响应更明显；同时 GmHKT1；2对不同逆境胁迫(低温、干旱、高盐和 ABA)也有较强的响应。蛋白结构分析表明,仅 GmHKT1；2具有4个 MPM 结构域,4个保守的氨基酸残基空间上形成一个“漏斗样”结构,充当 K+/Na+转运通道,通过邻近的 ATP 结合结构域,为 K+/Na+转运提供能量。基因结构分析显示,这些基因均含3个外显子和2个内含子,不同基因间的第一个外显子和内含子片段大小差异显著,导致各基因的基因组 DNA (gDNA)大小各异。启动子分析揭示,大豆 TRK-HKT 家族成员包含参与种子功能定位和各种激素及逆境胁迫应激反应的重要顺式作用元件；进化上该家族基因位于第一进化分支,含保守的Ser–Gly–Gly–Gly 基序。
식물 TRK-HKT 가족기인엄범개도식물 Na+/K+운수,삼여식물내역경협박조공。본연구이6개대두갑이용효솔차이품충위재료,이용 in silico 기술극륭도4개대두 TRK-HKT 가족성원(GmHKT1；1、GmHKT1；2、GmHKT1；3화 GmHKT1；4),채용 qRT-PCR 기술해석저사기인재저갑급역경협박하적표체궤제。결과표명, GmHKT1；2재대두유묘근중대저갑협박적향응명현고우기타3개기인,차갑고효대두품충저충향응경명현；동시 GmHKT1；2대불동역경협박(저온、간한、고염화 ABA)야유교강적향응。단백결구분석표명,부 GmHKT1；2구유4개 MPM 결구역,4개보수적안기산잔기공간상형성일개“루두양”결구,충당 K+/Na+전운통도,통과린근적 ATP 결합결구역,위 K+/Na+전운제공능량。기인결구분석현시,저사기인균함3개외현자화2개내함자,불동기인간적제일개외현자화내함자편단대소차이현저,도치각기인적기인조 DNA (gDNA)대소각이。계동자분석게시,대두 TRK-HKT 가족성원포함삼여충자공능정위화각충격소급역경협박응격반응적중요순식작용원건；진화상해가족기인위우제일진화분지,함보수적Ser–Gly–Gly–Gly 기서。
Plant TRK-HKT family genes are involved in Na+/K+ transportation and regulation to abiotic stresses. We used six soybean varieties with different potassium use efficiencies (PUE) as materials, cloned four soybean TRK-HKT family genes (GmHKT1;1, GmHKT1;2, GmHKT1;3, and GmHKT1;4) via in silico, and explored the genes structure and expression under low potassium treatment and abiotic stresses with qRT-PCR technique. The results showed that the expression level of GmHKT1;2 was higher than those of the other three members in the roots of soybean seedlings under low potassium stress, which was more ob-vious in the roots of the soybean varieties with high PUE. Meanwhile, GmHKT1;2 showed high response to various abiotic stresses (chilling, drought, high salinity, and ABA). Protein structure prediction showed that only GmHKT1;2 contains four MPM domains and a “funnel-like” structure of four conserved amino acid residues spatially, which acted as K+/Na+ transport channel and provided energy for transportation, together with the adjacent ATP binding domain. Analysis on gene structure indicated that there are three exons and two introns in all four members with a significant difference in the size of exon I and intron I, resulting in the genomic DNA (gDNA) difference in length of the different GmHKT genes. Promoter analysis revealed that upstream pro-moter elements of soybean TRK-HKT family genes contained important cis-acting regulatory elements involved in the functional target to seed-specific expression, and response to hormone and diverse abiotic stresses. In evolution, soybean TRK-HKT family genes belonged to clade I with conserved Ser–Gly–Gly–Gly motif.