共查询到18条相似文献，搜索用时 194 毫秒
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多聚半乳糖醛酸酶抑制蛋白(PGIP)是一种特异性结合和抑制真菌内切多聚半乳糖醛酸酶(endo-PG)活性的细胞壁结合蛋白。采用RT-PCR从嘉陵40(Morus atropurpurea Roxb.)果实中扩增PGIP基因c DNA,利用生物信息学的方法分析其编码蛋白的结构和功能。结果表明,嘉陵40PGIP开放阅读框全长1017 bp,编码338个氨基酸残基,被命名为MaPGIP1。MaPGIP1蛋白分子量37.9 k D,等电点为为6.65,信号肽为N端26个氨基酸残基,具有4个潜在的N-糖基化位点。MaPGIP1蛋白的核心区域由9个串联的LRRs基序组成。原核表达产物经SDS-PAGE分析,MaPGIP1蛋白以包涵体形式出现,Western blot证实了重组蛋白的特异性,经过Ni-NTA柱纯化和分步透析复性后获得可溶性蛋白,该蛋白能部分抑制果桑肥大性菌核病菌(Ciboria shiraiana)PG(Cs PG)活性,其最适pH值为4.5~5.0,最适温度30℃。抑菌试验结果表明,MaPGIP1蛋白在果桑肥大性菌核病菌菌丝侵染油菜叶片过程中具有一定的抑制效果。 相似文献
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果桑肥大性菌核病菌和油菜菌核病菌的交叉侵染、生物学特性及遗传关系 总被引：1，自引：0，他引：1
分别以果桑肥大性菌核病菌和油菜菌核病菌的子囊孢子交叉接种油菜和果桑。结果表明,杯盘菌子囊孢子能够侵染油菜,同样,核盘菌子囊孢子能够侵染果桑;在受侵染的桑椹上2种病菌均产生分生孢子梗和分生孢子,而在油菜上不产生。显微镜观察,杯盘菌的子囊盘外囊被切面为圆胞组织结构,核盘菌为角胞组织结构。SRAP分子标记和聚类结果表明,采自西南地区果桑上的杯盘菌和油菜上核盘菌基本各自聚在一类,其中一个杯盘菌分离物和一个核盘菌分离物聚在一类,表现特别。2种寄主上的病菌子囊孢子能相互侵染,因而果桑和油菜不能间套种植。 相似文献
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果实成熟衰老过程中软化机理研究进展 总被引：1，自引：0，他引：1
介绍了果实成熟衰老过程中呼吸作用、乙烯释放量、细胞壁超微结构和组分变化,以及与果实软化有关的细胞壁酶的活性变化。多数果实软化是由于细胞壁的破坏,细胞中的果胶溶液化,纤维素解体等。与果实软化相关较为密切的4种细胞壁酶:多聚半乳糖醛酸酶(PG)、β-半乳糖苷酶(β-Gal)、纤维素酶(Cx)和果胶甲酯酶(PME)。为深入研究果实软化机理提供参考。 相似文献
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核盘菌 [Sclerotinia sclerotiorum (Lib.) de Bary] 是引起油菜菌核病的病原真菌。核盘菌侵染植物细胞早期,可分泌一些细胞壁降解酶, 如不同类型的多聚半乳糖醛酸酶(polygalacturonase, PG)。这些酶对病菌在植物组织上的定植起关键作用, 同时酶活性的高低也决定病原菌的毒性或致病性。PG可以激活细胞的防卫反应而与其酶活性无关。为了解PG的信号转导途径, 利用RT-PCR方法克隆了核盘菌的PG基因, 将PG的编码区与酵母GAL4的DNA结合功能区融合, 构建到酵母诱饵蛋白表达载体PGBKT7中; 然后在酵母中构建了油菜cDNA表达文库。通过酵母双杂交方法在油菜cDNA表达文库中对与PG互作的蛋白进行了筛选, 分离到一个与PG互作的蛋白, 测序及BLAST分析表明该蛋白含有一个与钙离子结合的结构域, 称为C2结构域(C2-domain), 推测该蛋白是一种钙依赖的膜结合蛋白。该蛋白与拟南芥中一个含C2结构域功能未知蛋白的氨基酸同源性高达80.24%。利用半定量PCR分析了核盘菌诱导后该基因在油菜花、茎、叶中的表达, 结果表明该基因在叶片中表达量最高。克隆到的C2蛋白与其他物种中的C2蛋白比较发现, 与钙离子结合的天冬氨酸残基很保守。 相似文献
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苹果树腐烂病菌产生细胞壁降解酶的种类及其活性分析 总被引：6，自引：0，他引：6
通过对酶活性的分析,研究证实苹果树腐烂病菌在活体外和寄主体内均能分泌一系列的细胞壁降解酶:多聚半乳糖醛酸酶(PG)、果胶甲基半乳糖醛酸酶(PMG)、纤维素酶(Cx)、β-葡萄糖苷酶和木聚糖酶。不同碳源培养条件下,腐烂病菌产生细胞壁降解酶的活性及达到酶活性高峰的时间存在显著差异;诱导酶液对苹果愈伤组织具有明显的浸解作用,其中木聚糖为碳源产生的细胞壁降解酶,破坏能力最强。此外,研究发现,腐烂病菌在寄主体内产生细胞壁降解酶的活性变化规律不同,PMG和木聚糖酶在接种后最先被检测到活性显著升高,PMG酶活性于接种后第13天达到高峰,随后活性降低,而木聚糖酶和其他3种酶活性则随接种天数的增加活性不断增强;5种细胞壁降解酶中,Cx最大酶活性最低,而木聚糖酶活性最高,是其他酶最大活性的1.74～7.44倍。 相似文献
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调控果实成熟的基因工程研究进展 总被引：2，自引：0，他引：2
阐述了在果实成熟过程中与乙烯生物合成和细胞壁降解相关的酶（ACC合酶、ACC氧化酶、多聚半乳糖醛酸酶和果胶甲基酯酶）及其调控果实成熟的基因工程研究进展。 相似文献
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《华北农学报》2015,(5)
高油酸油菜和低油酸油菜对菌核病的抗性存在显著差异,为了弄清其分子机理,以一组高油酸油菜近等基因系自交授粉后20~35 d的种子为材料,分别进行转录组和同位素相对标记与绝对定量技术分析。分析了与抗病相关的氧化磷酸化、植物激素信号转导通路和植物病原体互作3个分类,将注释的基因和蛋白进行关联,并对其中可能与抗病相关的基因进行定量PCR验证。结合前人研究发现,基因表达或蛋白表达发生显著变化的基因gi|260505503(多聚半乳糖醛酸酶抑制蛋白)、gi|226346102(HSR203J类蛋白)、gi|470103214(钙调蛋白类)与抗病相关;而gi|297843222(结合蛋白)、gi|18397961(2-铁,2-硫-铁氧化还原类蛋白)、gi|196052306(还原型烟酰胺腺嘌呤二核苷酸脱氢酶亚基)、gi|18423437(还原型烟酰胺腺嘌呤二核苷酸脱氢酶(辅酶)1α-复形5)和gi|297794581(激酶家族蛋白)等基因差异显著。 相似文献
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S.S. ZaharahZora Singh 《Postharvest Biology and Technology》2011,62(3):258-266
The mode of action of nitric oxide (NO) in inhibiting ethylene biosynthesis and fruit softening during ripening and cool storage of mango fruit was investigated. Hard mature green mango (Mangifera indica L. cv. ‘Kensington Pride’) fruit were fumigated with 20 μL L−1 NO for 2 h at 21 °C and allowed to ripen at 21 ± 1 °C for 10 d, or stored at 13 ± 1 °C for 21 d. During ripening and cool storage, ethylene production and respiration rate from whole fruit were determined daily. The 1-aminocyclopropane-1-carboxylic acid (ACC) content, activities of ACC synthase (ACS), ACC oxidase (ACO), and fruit softening enzymes such as pectin esterase (PE), endo-1,4-β-d-glucanase (EGase), exo- and endo-polygalacturonase (exo-PG, endo-PG) as well as firmness and rheological properties of pulp were determined at two- and seven-day intervals during ripening and cool storage, respectively. NO fumigation inhibited ethylene biosynthesis and respiration rate, and maintained higher pulp firmness, springiness, cohesiveness, chewiness, adhesiveness, and stiffness. NO-fumigated fruit during cool storage and ripening had lower ACC contents through inhibiting the activities of both ACS and ACO in the fruit pulp. NO-fumigated fruit showed decreased activities of exo-PG, endo-PG, EGase, but maintained higher PE activity in pulp tissues during ripening and cool storage. In conclusion, NO fumigation inhibited ethylene biosynthesis through inhibition of ACS and ACO activities leading to reduced ACC content in the fruit pulp which consequently, reduced the activities of fruit softening enzymes during ripening and cool storage. 相似文献
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桑树EIN2基因的分离与表达 总被引：1，自引：0，他引：1
EIN2是植物体内乙烯信号转导的中心元件,负责将乙烯信号由内质网传递到细胞核中。本文通过检索桑树基因组数据,获得一个EIN2候选基因(MaEIN2),并进行生物信息学分析和表达分析。该MaEIN2全长5614 bp,由7个外显子和6个内含子组成,包含3921 bp的CDS,编码1036个氨基酸残基。MaEIN2在进化树中与草莓、桃树等双子叶植物的EIN2蛋白关系较近,与单子叶植物关系较远。MaEIN2在老叶和成熟果实中的表达量分别高于在幼叶和幼果中,且随果实发育呈逐渐上升趋势,MaEIN2可能与器官的成熟衰老有关。选用乙烯利、ABA和NaCl处理桑树种苗,乙烯利能够促进MaEIN2的表达,而ABA和NaCl抑制MaEIN2的表达。本文为深入研究MaEIN2基因的功能奠定了基础。 相似文献
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为了应对不良的外界环境,植物形成了一整套复杂的信号网络体系以适应变化的外界环境。其中MAPK级联是其中一个重要而保守的信号传导系统。采用RT-PCR策略,从干旱处理的油菜cDNA中克隆出全长的细胞分裂原激活的蛋白激酶基因。该基因命名为BnMPK9(GenBank登录号为AY737714),包含一个蛋白激酶区和一个保守的CD区。该基因与拟南芥AtMPK9高度同源,其激酶的磷酸化位点为TDY,同为D型MAPK亚家族基因。Southern杂交结果表明该基因在油菜基因组中拷贝数不少于2个。Northern杂交结果显示该基因能在不同的植物组织中表达。其表达受到甘露醇、紫外线和双氧水诱导上调表达,但低温和水杨酸处理后下调表达。实时RT-PCR分析表明甘露醇和双氧水能长时间诱导该基因高表达。在根中,甘露醇也能促进其上调表达。BnMPK9连接到pYES2.1酵母表达载体中转化酵母,发现增强了酵母对600 mmol L–1甘露醇和0.2 mmol L-1 tBuOOH的抗性。以上结果说明BnMPK9是MAPK基因家族中的一员,涉及真核生物细胞渗透和活性氧胁迫,并增强其抗性。 相似文献
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Haiyan Zhang Shaoyu Yang Daryl C. Joyce Yueming Jiang Hongxia Qu Xuewu Duan 《Postharvest Biology and Technology》2010,55(3):154-159
Experiments were conducted to examine softening and quality responses of harvested banana fruit to cold shock treatment intended to extend shelf-life. Fruit were immersed in ice-water for 1 h, then treated with or without 100 μL L?1 ethylene for 24 h at 24 °C, and finally stored at 20 °C. Fruit firmness, chlorophyll content, ethylene production, respiration rates, contents of pectin, starch and sugar, and the activities of the cell wall modifying enzymes polygalacturonase (PG), pectin methylesterase (PME) and CMCase (cellulase, endo-1,4-β-glucanase) were analyzed. Total amylase activity was also measured. Immersion in ice-water for 1 h effectively inhibited ripening-associated processes, including peel de-greening and pulp softening during storage or ripening. The delay in ripening was also manifest in reduced ethylene production and respiration rates. The inhibition of softening by cold shock treatment was related to decreased PG and PME activities, that is, retardation of pectin solubilization/degradation. Reduced activities of CMCase and total amylase and conversion of starch to sugar by ice-water immersion also contributed to the delay in softening of harvested banana fruit. 相似文献
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Akira Nakatsuka Tsuyoshi MaruoChihiro Ishibashi Yosuke UedaNobuo Kobayashi Masumi YamagishiHiroyuki Itamura 《Postharvest Biology and Technology》2011,62(1):89-92
Persimmon (Diospyros kaki Thunb.) fruit undergoes intensive cell wall modification during postharvest fruit softening. Xyloglucan metabolism is important in cell wall disassembly. We cloned cDNAs for two xyloglucan endotransglycosylase/hydrolase genes (DkXTH1 and DkXTH2) from ‘Saijo’ persimmon fruit treated with dry ice to remove astringency. In order to determine the ethylene dependence of XTH gene expression, fruit were exposed to 1-methylcyclopropene (1-MCP), an inhibitor of ethylene action, prior to removal of astringency. Ethylene production increased in mature control and 1-MCP-pretreated fruit after dry-ice treatment, and flesh firmness decreased to the same extent during dry-ice treatment in the control and 1-MCP-pretreated fruit. After dry-ice treatment, control fruit softened completely, but fruit firmness was maintained in 1-MCP-pretreated fruit. Accumulation of DkXTH1 mRNA was induced simultaneously with commencement of ethylene production in mature control fruit. Pretreatment with 1-MCP delayed accumulation of DkXTH1 mRNA. DkXTH2 expression also coincided with fruit softening but was intensified by 1-MCP treatment during the deastringency treatment. These results indicate that fruit softening was related to both DkXTH1 and DkXTH2 expression in ‘Saijo’ persimmons. 相似文献
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Na~+/H~+逆向转运蛋白基因SOS1(salt overly sensitive 1)是植物耐盐性的必需基因之一,在植物抵御盐胁迫过程中发挥十分重要的作用。本研究以小麦EST序列KJ563230为探针,利用电子克隆技术结合RT-PCR,获得一条甘蔗SOS1基因的cDNA序列,命名为ScSOS1(GenBank登录号为KT003285)。序列分析结果表明,该基因全长1403 bp,包含一个1272 bp的开放阅读框,编码423个氨基酸的蛋白质。ScSOS1蛋白的相对分子质量为47.6 kD,理论等电点(pI)为9.12。氨基酸序列分析表明,ScSOS1蛋白具有一个CAP-ED superfamily结构域。生物信息学预测显示,ScSOS1的编码蛋白为亲水性蛋白,不存在信号肽,二级结构元件多为无规则卷曲,主要参与中间代谢。实时荧光定量PCR分析表明,ScSOS1基因的表达具有组织特异性,在甘蔗叶鞘、蔗皮、蔗髓、侧芽和根中均有表达,其中在叶鞘中的表达量最高,根中的表达量最低。此外在NaCl、PEG、ABA、SA和MeJA的胁迫过程中,该基因表达均受到调控,其中受NaCl和PEG诱导后上调表达,均在24 h表达量达最高,分别约为对照组的1.5倍和4.0倍。推测该基因的表达与甘蔗耐盐性和抗渗透胁迫有关。 相似文献
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为揭示叶果间的内在作用规律,以桑树（Morus alba L.）当年生果枝为研究对象,分析不同大小果枝上叶片特征和果实性状的差异及其二者间的相互关系。结果表明：随着果枝由小到大,果枝上的叶片数与总叶干重显著增加,而叶形指数却无显著变化;桑葚数与总桑葚干重也有显著增加,桑葚含水量无显著变化。桑葚数与叶片数、总叶干重、总叶面积及其平均桑葚干重显著正相关。研究结果证实了果实的性状与叶片特征之间存在极密切关系。当年生果枝上的桑葚数量多少取决于果枝上的叶片总数,平均桑葚的干重则与果枝上的平均叶面积显著相关。 相似文献
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Jinhe Bai Anne PlottoRobert Spotts Nithiya Rattanapanone 《Postharvest Biology and Technology》2011,62(2):204-212
The objective of this study was to evaluate the use of an ethanol vapor release pad and a saprophytic yeast Cryptococcus infirmo-miniatum (CIM) to reduce decay and maintain postharvest quality of intact or fresh-cut sweet cherries (Prunus avium) cv. Lapins and Bing. Intact or fresh-cut fruit were packed in perforated clamshells (capacity 454 g) and stored at 1, 10 or 20 °C for up to 21, 14 and 8 d, respectively. For ethanol treatment, a pad made with silica gel powder containing 10 g ethanol and covered with perforated film, which allows ethanol vapor to diffuse gradually, was attached to the upper lid of the clamshells. Ethanol treatment caused accumulation of ethanol in the packaging headspace, about 10 μL L−1 with little change within 14 d at 1 °C, 23 μL L−1 at d 1 and decreased to 15 μL L−1 at d 10 at 10 °C, and 26 μL L−1 at d 1 and decreased to 13 μL L−1 at d 3 at 20 °C. Ethanol content in fruit was less than 9 mg kg−1 in all the control fruit, and increased to 16, 34 and 43 mg kg−1 in ethanol-treated fruit at 1, 10 and 20 °C, respectively. Nonetheless, a sensory taste panel did not perceive any flavor difference from the ethanol treatment. The ethanol treatment retarded softening, darkening, and acid decrease in fruit as well as discoloration of the stems, and extended shelf-life of intact cherries. Ethanol reduced brown rot (Monilinia fructicola) in fresh-cut cherries stored at 20 °C, but not at 1 and 10 °C. A pre-packaging dip in CIM completely controlled brown rot in inoculated fresh-cut cherries stored at 1 °C, and in naturally infected cherries at 20 °C. 相似文献