凝集素类受体蛋白激酶属于类受体蛋白激酶(RLKs)家族,在植物的抗病防御反应、生长发育、胞内信号传导以及非生物胁迫反应过程中发挥重要作用.实验室前期对过表达抗逆转录因子GmNFYB1大豆进行转录组测序,获得了差异表达基因GmLecRlk(Glyma.07G005700),其开放阅读框长度为546 bp,编码181个氨基酸,蛋白结构域分析显示其含有两个丝氨酸/苏氨酸激酶结构域,属于一种G型凝集素类受体蛋白激酶.实时荧光定量PCR结果显示,GmLecRlk基因在大豆的根、茎、叶、荚中均有不同程度的表达,在根中表达量最高;200 mmol/LNaCl处理下,GmLecRlk的mRNA丰度先降低后升高,在12 h时达到最高值,表明该基因参与大豆对盐胁迫的响应.利用发根农杆菌K599获得GmLecRlk过表达转基因发状根复合植株,在盐胁迫处理下,其存活率高于对照;在拟南芥中异源表达GmLecRlk基因,转基因拟南芥在盐胁迫处理下的萌发率、绿化率和根长均高于野生型拟南芥.综上所述,GmLec?Rlk参与大豆对盐胁迫的反应,过量表达基因能提高大豆和拟南芥的耐盐性,为培育和改良抗盐大豆新品种提供新的途径和理论指导.

泛素化系统通过介导蛋白质的翻译后修饰,参与包括细胞分化、激素应答、生物与非生物胁迫响应等多个生物学过程,其中含有U-box基因的泛素连接酶为泛素化系统的重要酶之一.课题组前期研究发现大豆Gly?ma.13G115900(GmPUB32)基因编码一个泛素连接酶(PUB),其表达量在根中受盐胁迫影响显著.本研究在大豆品种垦丰16中克隆得到大豆U-box家族基因GmPUB32,序列分析结果表明GmPUB32基因的开放阅读框长度为513 bp,编码170个氨基酸,在其83-131个氨基酸之间含有一个RING/U-box保守结构域;亚细胞定位分析结果显示Gm?PUB32蛋白定位于细胞膜与细胞质中;GmPUB32基因在大豆根、茎、叶片与荚果中均能检测到不同程度的表达,在根中表达量最高,GUS组织化学染色进一步明确其在根中发挥主要作用;荧光定量PCR分析结果显示,在200 mmol/L NaCl处理后,与对照相比随着处理时间的延长GmPUB32在根中的表达量呈现出显著的下降趋势,表明GmPUB32可能参与大豆对于盐胁迫的应答过程;通过对过表达GmPUB32的T3拟南芥的盐胁迫耐受性进行分析,结果表明转基因拟南芥的萌发率、子叶绿化率与盐胁迫下的存活率均明显低于野生型,此外,GmPUB32过表达转基因毛状根的生长速率相比野生型也明显受到抑制.由此推断,GmPUB32可能作为负调控因子参与大豆对于盐胁迫的应答过程,降低植物对于盐胁迫的耐受性.

•Circular RNAs were identified in a whole genome in soybean.•The existence of circular RNAs were validated in cold-stressed soybean.•Circular RNAs were predicted to be involved in low temperature responses.•Circular RNAs were found to act as the sponges for miRNAs in soybean.•Circular RNAs were found to have protein-coding potential in soybean.

Cold stress is a major abiotic factor that inhibits soybean ( Glycine max (Linn.) Merr.) yield. MicroRNAs (miRNAs) are prevalent endogenous gene regulators in eukaryotes that can cleave target messenger RNAs and play essential roles in soybean cold response. In this study, 105 genes, including 22 pentatricopeptide repeat ( PPR ) genes and 4 growth-related genes, were predicted to be the target genes of soybean miRNA miR1508a ( gma-miR1508a ). The expression of gma-miR1508a was induced by cold treatment but inhibited by drought stress. Compared to the wild type (WT), the overexpression of gma-miR1508a in soybean plants resulted in dwarfing and thick cell walls. Gma-miR1508a transgenic plants exhibited cold tolerance at the germination and young seedling stages, and soluble sugar content was 58.7% higher than that of WT plants under cold stress. The gma-miR1508a transgenic lines showed lower survival rates and greater leaf water loss compared to the WT under drought treatment, which indicated that gma-miR1508a reduced drought resistance in soybean. Transcript abundances of 2 PPR and 4 growth-related predicted target genes decreased in gma-miR1508a transgenic plants. In the above six genes, the expression patterns of Glyma.16G162100 ( PPR ) and Glyma.17G065400 (xyloglucan endo-trans-glucosylase/hydrolase, XTH ) showed opposite trends with gma-miR1508a under cold conditions. 5′-Rapid amplification of complementary DNA ends (5′-RACE) assays of Glyma.16G162100 revealed that the cleavage sites of gma-miR1508a are located at the 15th and 21st nucleotides of the complementary region. This study demonstrated that gma-miR1508a confers dwarfing, cold tolerance, and drought sensitivity in soybean.

植物液泡铁离子转运蛋白可维持细胞内铁离子含量,保证细胞正常生长,在植株抵抗盐碱环境过程中发挥重要作用.在大豆中克隆得到液泡铁离子转运蛋白同源基因GmVIT1,蛋白结构域分析结果表明,GmVIT1属于CCC1蛋白超家族,具有高度保守的结构域.研究发现GmVIT1具有跨膜结构,并利用YFP荧光蛋白确定GmVIT1蛋白定位在液泡膜上;实时荧光定量PCR(qRT-PCR)显示,GmVIT1在大豆根、茎、叶、花、荚和种子中均表达,花中mRNA丰度相对较高;胁迫后发现,GmVIT1的mRNA积累受ABA负调控,盐胁迫下基因显著上调表达.大豆毛状根试验发现,过量表达GmVIT1的毛状根耐受150 mmol·L-1氯化钠;转基因拟南芥耐盐性试验表明GmVIT1可显著提高植物耐盐能力.

选用20份大豆品种,利用PEG6000模拟干旱、旱棚盆栽方式,分别统计芽期、苗期和花期发芽率、生理、叶绿素荧光等指标,收获后测定农艺性状,同时利用抗旱系数、抗旱指数、隶属值函数法综合分析抗旱性.结果 表明,不同指标或方法在大豆抗旱性鉴定中的作用存在差异,不同品种不同生育期抗旱性存在差异.综合评价全生育期抗旱性,最终筛选出3个高抗旱型品种:龙品03-311、晋豆21和艾卡166;2个抗旱型品种:绥农14和铁丰8;3个干旱敏感型品种:猫眼豆、合丰47和东农594.

Light is one of the most important environmental factors for the growth and development of plants. To adapt to changes in day length, the photoreception and transmission of the light signals in plants mainly depend on the various light receptor proteins. The PAS/LOV protein (PLP) has a PAS domain in the N-terminal and LOV domain in the C-terminal and has been confirmed as a new type of blue light receptor in Arabidopsis thaliana. However, the role of its counterpart in soybean remains largely unclear. In this study, the expression pattern of the GmPLP1 under different light qualities was determined by real-time RT-PCR analysis using the cultivar 'DongNong 42', a photosensitive soybean cultivar, suggesting that GmPLP1 was affected by the circadian clock and was a dark-induced gene. Moreover, the mRNA abundance increased significantly under blue light. Further analysis revealed that overexpression of GmPLP1 displayed the inhibition of hypocotyl elongation under blue light, and the expression of CRY1, CRY2, CKL3, CKL4, BIT1, and HY5 were simultaneously increased in GmPLP1-transgenic Arabidopsis, suggesting that the shortened hypocotyl was associated with the up-regulation of these genes. Taken together, our results suggest that GmPLP1, which is a new possible type of blue light photoreceptor in soybean, plays an important role in the blue light signaling pathway.

本研究将大豆中调控光周期途径的关键基因GmGI转入Havana 425烟草中,以非转基因Havana425烟草为对照,对获得的转GmGI基因T3代烟草的4个株系的花期、产量以及其它农艺性状统计分析.结果表明,与非转基因烟草对照相比,除GI6株系外,其余3个株系株高与单株粒重提升明显,花期平均提前了31.5 d.上述结果表明:GmGI基因使植物的花期提前的同时提高了植物的产量,因而该基因对于改良植物的光敏感特性,打破品种种植的地域限制、选育高产的优良品种是一个重要的基因资源.