镁对大豆游离脯氨酸、可溶性糖和可溶性蛋白质含量的影响

采用水培试验方法 ,研究了不同镁营养水平下 ( 0 .0 0 ,0 .0 1 ,0 .1 0 ,1 .0 0 ,1 0 .0 0 ,1 0 0 .0 0mg/L) ,2个大豆品种 (浙春 2号和浙春 3号 )在 2个生育时期 (五叶期和盛花期 )叶片内游离脯氨酸、可溶性糖和可溶性蛋白质含量的变化。结果表明 :在缺镁胁迫下 ,大豆叶片的脯氨酸含量显著增加 ,可溶性糖含量急剧下降 ,可溶性蛋白质含量也有所下降 ;施镁则有利于提高大豆叶片可溶性糖和蛋白质含量 ,而脯氨酸含量则明显下降 ,其中适量的镁 ( 1 0 .0 0mg/L)对其改变效果最为明显。     

脯氨酸累积与植物的耐盐性

渗透调节能力是植物耐盐性的最基本特征之一.笔者就近年来有关植物体内重要渗透调节物质脯氨酸累积及其累积机理、脯氨酸累积的生理作用与植物渗透调节、耐盐性关系的研究进展进行了系统综述.     

低温对花生幼苗渗透调节物质和保护酶活性的影响

在实验室模拟低温条件下,对花生幼苗体内渗透调节物质含量和保护酶活性进行了研究。结果表明:随着低温处理时间的增加,花生真叶中脯氨酸和可溶性糖含量呈上升趋势,以10℃胁迫组增加最为明显;可溶性蛋白和子叶中可溶性糖呈现先升后降趋势;超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性明显高于对照组;过氧化物酶(POD)活性呈现先降后升趋势,3种酶在低温胁迫中表现出一定的协同作用。     

外源脯氨酸对NaCl胁迫下番茄幼苗光合特性的影响

[目的]为了研究外源脯氨酸对Na Cl胁迫下番茄叶片光合特性的影响。[方法]以番茄"中蔬四号"为材料,测定其叶绿素含量和光合特性。[结果]叶绿素含量随着盐浓度的升高先增加后减少。一定浓度的外源脯氨酸可以延缓叶绿素含量下降的趋势。细胞间CO2浓度随着盐浓度的增加先下降后上升,净光合速率、气孔导度和蒸腾速率随盐浓度的增加而下降。[结论]外源脯氨酸可以提高盐胁迫番茄幼苗的细胞间CO2浓度、净光合速率、气孔导度和蒸腾速率。     

在盐胁迫下获得的大豆愈伤组织及再生植株的生化反应

在含NaCl的选择培养基中获得的大豆小真叶愈伤组织及再生植株的过氧化物酶活性增高,蛋白质含量降低,愈伤组织中的脯氨酸含量随NaCl浓度增高而急剧上升。在盐胁迫下过氧化物酶活性和脯氨酸含量增高,蛋白质含量降低是对盐胁迫的生理适应。     

GA3 and Proline Promote Germination of Wheat Seeds by Stimulating α-Amylase at Unfavorable Temperatures

abstract

The effects of various constant temperatures (4, 9, 14, 19, 24, 29, 34, and 38°C) on the germination of winter wheat seed ( Triticum aestivum L. cv. ‘Koyuki’) in a dark condition were studied. The maximum germination percentage was 98% at 24°C. The speed of germination was fastest at 29°G. These results indicate that the most suitable temperature for germination was in the range of 24 to 29°G. α-Amylase expression during germination was also high at higher temperature, and maximum expression occurred at 29°C, although a high temperature of 38°C prevented the synthesis of α-amylase. The close correlation between germination and α-amylase activity at various temperatures indicates that α-amylase is an essential factor for the temperature-dependent germination of wheat seed. In contrast, accumulation of proline increased at a lower temperature, and was the highest at 4°G. We also studied the effects of gibberellin (GA₃) and proline, a compatible osmotica in alleviating the effect of low and high temperature stresses. Pre-soaking treatment with GA3 and proline was effective in promoting germination and increasing α-amylase expression at a low (4°C) and high (38°C) temperature. These results suggest that GA₃ and proline exhibit positive effects on stress alleviation through the stimulation of α-amylase expression.     

甘蓝型油菜P5CSb和OAT基因在干旱胁迫下的表达分析

为了探明脯氨酸积累过程的分子机制,以耐旱性较强的甘蓝型油菜holiday为材料,应用酸性茚三酮染色法和RT-qPCR(实时荧光定量PCR,real-time quantitative PCR)技术分别检测在干旱胁迫0d(对照组)、1d、3d、5d、7d油菜根、茎、叶、花和青荚中脯氨酸含量以及控制其合成的关键基因P5CSb和OAT的表达量。结果表明,各器官中脯氨酸的含量和干旱胁迫时间成正比,不同器官中脯氨酸的含量存在明显的差异;P5CSb基因和OAT基因的表达量在不同器官中呈现表达特异性,P5CSb基因在青荚中随着干旱时间的增加无明显变化,在叶中逐渐上升,在其他器官中均表现为先升高后降低的趋势,OAT基因的表达量在茎中无明显变化,在叶和花中呈现先升高后降低趋势,在根和青荚中表现为上升趋势;三者对比结果显示,P5CSb基因和OAT基因共同控制脯氨酸的合成,且不同胁迫时间,2个基因所起的作用不同,其中P5CSb基因占主导地位。     

Fractionation of tryptic gliadin hydrolysates based on proline levels

The central domain (CD) and terminal domains (TDs) of wheat gliadins contain high and low levels of the amino acid proline (Pro), respectively. The CD is rather hydrophilic while the TDs are rather hydrophobic and contain most of the ionisable amino acids, although present only in low levels. Therefore, peptides derived from the CD or TDs may strongly differ in their physico–chemical properties. Trypsin cleaves peptide bonds at lysine and arginine residues which are mainly present in the TDs and was used in the present study. Several fractionation methods were examined to isolate CD and TD related peptides from tryptic hydrolysates. Pro was used as a marker for CD and TD related peptides. Both semi-preparative reversed-phase HPLC separation and fractionation of the water-soluble peptides of the tryptic gliadin hydrolysates by graded ethanol precipitation resulted in peptide fractions with different Pro levels. Whereas the fractions precipitating up to 90% ethanol were Pro rich, a Pro poor fraction consisting of small peptides was soluble in 90% ethanol solution. The water insoluble peptides of the tryptic hydrolysates also showed a low Pro level. Ultrafiltration of the water-soluble peptides using a 5-k membrane resulted in small Pro poor peptides and larger Pro rich peptides.     

宜兴百合叶片与鳞茎对干旱胁迫的生理响应(摘要)(英文)

[目的]探索百合耐旱性评价的有效方法,为百合抗旱品种筛选提供参考。[方法]通过人工模拟干旱胁迫环境,研究宜兴百合在土壤不同含水量的条件下,叶片和鳞茎脯氨酸含量、丙二醛含量、还原性糖含量等生理指标的变化。土壤含水量、丙二醛含量、游离脯氨酸含量和还原性糖含量分别采用烘干法、硫代巴比妥酸法、磺基水杨酸法和菲林试剂比色法测定。[结果]将宜兴百合在该试验中的干旱胁迫强度分为轻度胁迫(A-C,长势基本不受影响)、中度胁迫(C-D,长势稍差,复水后基本恢复生长)、重度胁迫(D-E,地上部分长势受到严重影响,复水后能复活,但长势差)、致死性胁迫(E-G,地上部分叶片发黄、卷曲、枯死,复水后地上部分也不能存活,鳞茎进入休眠状态)等几个阶段。①叶片丙二醛含量在轻度胁迫(A-C)时上升,在接近轻度胁迫后期,丙二醛含量上升速度加快,并达到最高水平;中度胁迫期间(C-D)下降到较低水平;重度胁迫(D-E)期间,丙二醛含量重新上升;致死性胁迫(E-G)前期(E-F)下降,后期(F-G)维持较低水平。鳞茎丙二醛含量在整个干旱胁迫期间,随干旱胁迫强度的增加而增加,增加过程平缓。②叶片脯氨酸含量在轻度胁迫期间(A-C)上升,至轻度胁迫后期达最高水平;中度胁迫(C-D)、重度胁迫期间(D-E),脯氨酸含量持续下降,至重度胁迫后期达最低水平;致死性胁迫期间(E-G),脯氨酸含量虽有较小变化,但基本维持较低水平。鳞茎脯氨酸水平在干旱胁迫期间呈上升趋势,但上升幅度不大。具体过程是,在轻度胁迫后期(C)上升速度加快,并达最高水平;中度胁迫(C-D)及重度胁迫期间(D-E),有轻微下降,致死性胁迫期间(E-G)又有轻微上升;从轻度胁迫后期直到致死性胁迫期间,基本维持较高水平。③叶片和鳞茎在不同强度干旱胁迫下还原性糖的响应规律相似对不同强度的干旱胁迫的变化值较小。轻度胁迫含量下降,中度胁迫期间有轻微上升;重度胁迫期间下降,致死性胁迫含量变化不大,整体趋势是随胁迫强度的增加呈现下降。宜兴百合的叶片对干旱胁迫的响应性比鳞茎好,脯氨酸含量、丙二醛含量对干旱胁迫的响应性比还原性糖含量好。[结论]与鳞茎相比,宜兴百合的叶片为较好的用于耐旱性评价分析的材料,能较好地反映百合对干旱胁迫的生理响应;耐旱性鉴定指标中,丙二醛和脯氨酸是较好的鉴定指标,对干旱胁迫强度的响应性好。     

Water deficit and polyethylene glycol 6000 affects morphological and biochemical characters of Pelargonium odoratissimum (L.)

The effects of water deficit and polyethylene glycol (PEG) 6000 on the growth and content of essential oil, photosynthetic pigments, soluble sugars, proline, macroelements (N–P–K) and microelements (Mg–Zn–Fe–Mn) of Pelargonium odoratissimum (L.) plants were investigated. Water deficits of 80% and 40% of field water capacity decreased certain growth characters (total leaf area, leaf number, and total fresh and dry mass). The photosynthetic pigments (chlorophylls a and b, total carotenoids) and mineral content (N–P–K–Mg–Zn–Fe–Mn) also decreased as water deficit level increased. Water deficit promoted the accumulation of essential oil content and its main components (methyl eugenol, isomenthone and limonene) as well as total soluble sugars and proline contents. The water deficit × PEG 6000 interaction was greater than water deficit treatments alone on all plant growth characters assessed.