IP_3敏感的钙离子通透性通道参与茉莉酸诱导的钙动员

[目的]研究茉莉酸诱导的钙动员通往IP3敏感的钙离子通透性通道的作用。[方法]以低温导入法将钙离子荧光探针Fluo-3/AM导入拟南芥叶片细胞中,利用LASAF（Leica Application Suite-Advanced Fluorescence）软件记录肝素对茉莉酸（JA）诱导的胞内钙离子荧光强度的变化。[结果]经不同浓度的肝素预处理后,拟南芥叶细胞中胞内钙离子的荧光强度降低,再用100μmol/LJA处理时,其荧光强度升高,但仅与未经肝素处理的荧光强度相当。[结论]肝素预处理可抑制JA诱导的胞内钙离子浓度的升高。     

农杆菌蘸花法侵染拟南芥的研究

为探索拟南芥转化法的广泛性,使其能转化其它植物,研究了转化试验中的一些参数.结果表明:农杆菌渗透转化拟南芥成功的3个关键因素是:适当的植株发育时期,即花蕾期;5%的蔗糖;0.05%的Silwet L-77.该种方法可适用于多种生态型的拟南芥植物转化,便于快速获得带有T-DNA标记的植株,并为植物的转基因技术提供一定的参考依据.     

AtAHA10参与拟南芥幼苗盐胁迫响应的信号转导机制初探

为了探究质膜质子泵AHA10在盐胁迫响应中的作用,本试验以拟南芥AHA10缺失突变体aha10-1幼苗为材料,检测了盐胁迫条件下幼苗根和子叶的生长状况。结果显示,aha10-1幼苗在0.1mol/L NaCl处理条件下,主根长度明显短于野生型,子叶生长状况与野生型相同,说明AHA10可能在幼苗根盐胁迫响应过程中发挥了正向调节作用。电生理检测结果显示,盐处理后野生型根细胞质膜钙电流明显增强,而aha10-1根细胞质膜钙电流未见明显变化,表明AHA10可能在盐胁迫激活钙信号过程中发挥了介导作用。     

甘蓝型油菜BnaSOT12a基因的抗性作用研究

磺酸转移酶(SOT,EC2.8.2.–)催化的磺酸化反应在植物的生长发育和植物抗逆过程中起着重要的作用。甘蓝型油菜BnaSOT12a基因是与拟南芥中AtSOT12基因同源的一个磺酸转移酶基因。为探寻BnaSOT12a基因的抗性相关功能,对其在油菜中不同部位的表达和在拟南芥中过表达情况下对转基因植株的影响进行了分析。结果显示:BnaSOT12a基因在甘蓝型油菜的根、叶、花芽和花中都有表达,其在花中的表达量最高,而在茎与果荚中没有表达;甘蓝型油菜BnaSOT12a基因在拟南芥中的过表达,能提高转基因植株在发芽和根生长方面对NaCl胁迫的耐受能力,但在盐胁迫下,BnaSOT12a的磺酸化作用并不影响拟南芥中抗病途径的信号传导,与抗病途径无关。     

花粉管通道法介导的真菌耐盐基因转化拟南芥

橡胶树内生真菌ITBB2-1具有很强的抗盐性,在培养基中添加2倍海水盐度的NaCl能显著促进菌落的生长。采用两种方法研究利用花粉管通道法将ITBB2-1耐盐基因导入拟南芥。多数耐盐转基因植株畸形,生长发育不正常。通过对一千两百余株转基因植株的筛选,获得了耐盐性显著提高、生长发育正常的转基因植株3个。对主要农艺性状统计分析发现,转基因植株叶片的长度、宽度和面积均比野生型植株小,差异达极显著水平。转基因植株SR3的角果长度仅为野生型的64．5％,SR1和SR2的角果长度与野生型无显著差异。本研究表明,在真菌耐盐机制尚未得到研究和耐盐基因尚未克隆的情况下,可以采用花粉管通道法将其耐盐特性导入高等植物中。     

磷脂酶Dβ在拟南芥低温信号中的转导作用

磷脂酶D（PLD）不仅是植物中一类主要的磷脂水解酶,而且是一类重要的跨膜信号转导酶类。PLD的磷脂降解功能和信号转导功能均影响植物的抗冻性。本研究以PLDβ基因被敲除的拟南芥突变体及其野生型植株为材料,进行低温驯化和冻害胁迫处理,并分析其作用途径。结果表明,PLDβ基因介导低温信号转导作用,参与渗透调节途径中脯氨酸的调控和抗氧化系统中过氧化氢酶（CAT）活性的调控,并且与低温信号激素ABA不在同一条信号转导途径。本研究为探索通过调控PLD的活性提高植物抗冻性提供了新的途径,并为深入揭示植物的抗冻机理以及磷脂信号转导机制提供实验支持。     

Transformation of Arabidopsis thaliana via Agrobacterium tumefacience with an endochitinase gene from Trichoderma, and enhanced resistance to Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is an important pathogen to many crops and is especially damaging to rape in China. As a model plant Arabidopsis thaliana (Col0) was transformed by spraying Agrobacterium tumefacience with Trichoderma endochitinase gene ThEn-42 at initial bud stage. Eleven seedlings (corresponding to about 0.22 percent transformation) exhibited resistance to hygromycin. The DNA fragment unique to endochitinase (ThEn-42) was amplified by Arabidopsis leaf-PCR or genomic DN…     

Regulation and function of AtNRAMP4 metal transporter protein

The NRAMP gene family encodes integral membrane proteins mediating the transport of a broad range of transition metals in bacteria, fungi, plants, and animals. We studied the regulation of AtNRAMP4 in Arabidopsis. In a previous study, we showed that AtNRAMP3 and AtNRAMP4 transport manganese (Mn), iron (Fe), and cadmium (Cd). In this study, we show that, in contrast to AtNRAMP3, AtNRAMP4 complements the growth phenotype of the zrt1zrt2 Zn uptake deficient yeast mutant. In a previous study, we have shown that, under Fe starvation, AtNRAMP4 mRNA levels are up-regulated in Arabidopsis. To analyze the regulation of AtNRAMP4 at the protein level, we generated specific antibodies against AtNRAMP4 protein. The antiserum was able to recognize a tagged version of AtNRAMP4 expressed in yeast. The antibody did not reveal any change in AtNRAMP4 protein level upon Fe starvation in Arabidopsis thaliana ecotype Columbia plants. In AtNRAMP4 overexpressing plants, high levels of AtNRAMP4 protein could be detected. AtNRAMP4 overexpressing plants display cadmium hypersensitivity in a medium containing 50 μm FeEDTA as Fe source. However, despite the constitutive accumulation of AtNRAMP4 protein, AtNRAMP4 over-expressing plants did not display Cd hypersensitivity under high Fe supply (100 μm FeHBED). AtNRAMP4 over-expressing lines displayed the same sensitivity to Zn as controls under all conditions tested. Our results suggest a translational level for the regulation of AtNRAMP4. Over-expression of AtNRAMP4 in Arabidopsis thaliana confers a slight hypersensitivity to Cd but not to Zn.