木瓜秀粉蚧为害对不同木薯品种次生代谢物质含量的影响

次生代谢物质在植物防御植食性害虫时发挥重要作用,但目前尚无次生代谢物质与木薯品种抗虫相关性的报道。本研究系统开展了木瓜秀粉蚧为害前后不同木薯品种叶组织中总酚、丙二醛、单宁等次生代谢物质含量的差异分析。结果表明,与为害前相比,木瓜秀粉蚧为害1、4、8 d后,感虫木薯品种‘BRA900’‘面包’‘SC205’和‘瑞士T7’叶组织中总酚与丙二醛含量无显著差异,单宁含量则显著降低,而抗虫木薯品种‘缅甸’和‘C1115’叶组织中总酚和单宁含量显著增加,丙二醛含量显著降低。抗虫木薯品种的总酚含量在粉蚧为害前显著低于感虫木薯品种,而粉蚧为害1、4、8 d后显著高于感虫木薯品种;抗虫木薯品种丙二醛含量在为害前与感虫木薯品种无显著差异,粉蚧为害1、4、8 d后显著低于感虫木薯品种;抗虫木薯品种单宁含量在为害前后均显著高于感虫木薯品种。相关性分析发现,木薯对木瓜秀粉蚧的抗性与叶组织中总酚含量和单宁含量显著正相关,与丙二醛含量显著负相关。本研究初步阐明基于次生代谢物质总酚、丙二醛、单宁的木薯品种对木瓜秀粉蚧的抗性机理。     

土壤含水量对狗牙根叶片生理生态指标的影响

采用盆栽控水试验,研究了不同土壤含水量（水淹,23%,18%,13%,8%）对我国雅砻江库区重要植物物种狗牙根叶片光合色素、SOD活性、POD活性、脯氨酸和MDA含量变化的影响。结果表明:与对照（23%）相比,狗牙根受到淹水胁迫时叶绿素a,b的含量和光合效率有所下降,丙二醛含量有所升高,但是抗氧化酶活性以及脯氨酸含量的增大提高了植物对淹水胁迫的抵抗力。随着土壤含水量的减少,叶绿素a和b的含量、光合速率、SOD、POD活性和丙二醛含量先升高,随后逐渐降低。SOD和POD活性在8%时存在最低值,分别为33.10U/gFW和3.87U/gFW。Carotenoid/Chlorophyll（Car/Chl）比值在18%时达到最低值0.22,然后增大。脯氨酸（Pro）含量随胁迫程度呈明显的增大趋势,并在8%达到最大值0.31μg/gFW,说明干旱条件时狗牙根通过提高类胡萝卜素和脯氨酸含量来改善渗透调节能力,增强对干旱胁迫的抵抗能力和适应力。但严重的干旱胁迫（8%）导致了植物叶片的损伤。     

灌浆结实阶段水分逆境对超级稻叶片丙二醛含量的影响

通过水份仪结合称重法人为控制土壤水分的盆栽试验,研究灌浆结实阶段水分逆境对不同类型超级稻品种叶片丙二醛(MDA)含量的影响.结果表明:水稻灌浆结实阶段对水分的敏感性较强,开花至花后30 d不同时段的水分逆境均导致叶片丙二醛含量显著增加,尤其花后30 d时叶片丙二醛含量较对照增加更为明显.不同水分条件下各品种倒二叶的丙二醛含量也均显著高于剑叶,水分逆境导致水稻叶片尤其是倒二叶的丙二醛含量显著升高,叶片膜脂过氧化程度增强,加速了叶片的衰老进程.不同品种由于对水分逆境响应的敏感性差异而受影响的程度不同,相对于普通杂交稻汕优63来说,超级稻品种受到的影响要小.     

Effects of humic acid on remediation of the nutritional deficiency of gerbera in hydroponic culture

Information is scant on the effect of humic acid (HA) on physiological, antioxidant and photosynthesis attributes of gerbera plants undergoing nutrient deficiency in culture solution. Gerbera plants cv. Malibu were grown in a factorial experiment based on a completely randomized design with 3 replications, using 3 different nutrient solutions [complete nutrient solution (NSc), 25% NSc (NS1), and 50% NSc (NS2)] treated with 2 levels of humic acid [0 (HA0) and 500 mg/l (HA1)].The interaction effect of HA and NS showed that HA improved the flower number in NSc, the transpiration in NS1+HA1, photosynthesis rate in NSc+HA1, stomatal conductance (gs) in NS2, mesophyll conductance of leaves in all NS levels and photosynthetic water use efficiency in NSc+HA1. The interaction effect of nutrient solution and HA on antioxidant activity was inconclusive, malondialdehyde content was the highest in NS2 and the lowest in NS1+HA1. The peroxidase activity increased in complete nutrient solution with and without HA and there were no differences among other treatments. Superoxide dismutase activity increased in NS1 and complete nutrient solution with HA and reached the highest in NSc. Humic acid was more effective in nutrient uptake, i.e., nitrogen, phosphorus, potassium, calcium, zinc, and iron (N, P, K, Ca, Zn, and Fe) in complete nutrient solution compared to NS1 and NS2. Conclusively, humic acid can compensate the nutrient deficiency stress of the culture solution in regards to protein synthesis, photosynthesis attributes regardless of the nutrient uptake of gerbera.     

脱落酸通过提高抗氧化酶活性与基因表达参与富氢水增强番茄幼苗抗旱性

以15%聚乙二醇6000(PEG-6000)处理模拟干旱胁迫,研究了氢气(H₂)和脱落酸(ABA)在番茄(Solanum lycopersicum L.)幼苗抵抗干旱胁迫中的作用及其相互关系。结果表明,外源H₂和ABA均可促进番茄在干旱胁迫下的生长,其中富氢水(HRW,H₂供体)和ABA最适浓度分别为75%和150μmol·L^-1。干旱胁迫下,HRW处理能显著增加番茄幼苗叶片内源ABA含量及其关键基因表达。同时,HRW和ABA单独及其共同处理的番茄幼苗叶片丙二醛(MDA)含量较PEG处理分别降低了34.8%、32.6%和37.0%;而超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)的活性及其基因表达显著高于PEG处理。另外,ABA抑制剂氟啶酮(FLU)抑制了HRW对干旱胁迫下番茄幼苗生长的促进作用,说明H₂促进干旱胁迫下番茄幼苗的生长可能需要ABA的参与。FLU抑制了HRW对干旱胁迫下叶片MDA含量的降低作用。此外,FLU抑制了HRW对干旱胁迫下叶片...     

Effects of dietary polyunsaturated fatty acid/vitamin E (PUFA/tocopherol ratio on antioxidant defence mechanisms of juvenile gilthead sea bream (Sparus aurata L., Osteichthyes, Sparidae)

Lipid peroxidation, specifically polyunsaturated fatty acid (PUFA) oxidation is highly deleterious, resulting in damage to cellular biomembranes, and may be a principal cause of several diseases in fish including jaundice and nutritional muscular dystrophy. Tissue lipid PUFA content and composition are critical factors in lipid peroxidation, as is the level of endogenous antioxidant molecules such as vitamin E. The primary objective of the present study was the characterization of antioxidant systems in a cultured juvenile marine fish, gilthead sea bream (Sparus aurata) with the underlying aim to understand how to avoid oxidation problems that may cause pathologies and disease and so to enhance growth and quality of early ongrowing stages. Juvenile sea bream were fed diets having either high or low levels of fish oil and supplemented or basal levels of vitamin E with PUFA/vitamin E ratios ranging from 117±12 in the diet with low PUFA supplemented with vitamin E to 745±48 in the diet with high PUFA with no additional vitamin E. None of the diets had serious deleterious effects on growth or survival of the fish, but the different dietary regimes were effective in significantly altering the PUFA/vitamin E ratios in the fish livers with values ranging from 5.7±0.4 in fish fed the diet with low PUFA supplemented with vitamin E to 91.1±13.2 in fish fed the diet with high PUFA with no additional vitamin E. This had effects on the peroxidation status of the fish as indicated by the significantly altered levels of in vivo lipid peroxidation products measured in liver, with fish fed the diet rich in PUFA and low in vitamin E showing significantly higher values of thiobarbituric acid reactive substances (TBARS) and isoprostanes. The isoprostane levels generally followed the same pattern as the TBARS levels supporting its value as an indicator of in vivo oxidative stress in fish, as it is in mammals. However, few significant effects on antioxidant enzyme activities were observed suggesting that more severe conditions may be required to affect these activities such as increasing the PUFA/vitamin E ratio or by increasing peroxidative stress through the feeding of oxidized oils.     

不同储藏条件下糙米品质变化研究

将供试3种糙米(粳米、杂籼米和纯籼米)分别放在低温、常温、高温和真空条件下储藏,定期测定其浸出液电导率和丙二醛含量的变化.随着储藏时间的延长,糙米的浸出液电导率呈增加趋势,低温储藏的增加最小,真空储藏的次之,常温储藏的增加较大,高温储藏的增加最大;低温、常温和真空储藏条件下丙二醛含量随着储藏时间延长而增加,高温条件下先增加后减小.     

胆固醇对水稻幼苗抗冷性的影响

低浓度的胆固醇处理水稻种子,可增强冷害水稻幼苗的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性,降低丙二醛（MDA）含量,提高可溶性蛋白总量中的热稳定蛋白含量,但过氧化物酶（POD）活性变化不明显。亚细胞组分测定表明,ATP主要存在于叶绿体和线粒体中,胆固醇对低温下叶绿体的保护作用尤为明显。     

低温胁迫对玉米幼苗脯氨酸、丙二醛含量及电导率的影响

文章研究了低温胁迫条件下,东农250、四密21及屯玉88玉米幼苗叶片中脯氨酸(Pro)、丙二醛(MDA)含量和相对电导率(EC)动态变化。结果表明,不同强度低温胁迫后,不同品种MDA含量与EC均呈增加趋势,屯玉88增加的幅度要明显高于四密21与东农250;Pro也呈增加趋势,但东农250Pro增加量却显著高于四密21与屯玉88。本试验采用的3个玉米品种抗低温冷害能力由强到弱依次为:东农250、四密21、屯玉88。     

PEG6000模拟干旱胁迫对大麦幼苗丙二醛含量及保护酶活性的影响

[目的]模拟干早胁迫下对不同大麦品种幼苗丙二醛(MDA)含量以及保护酶活性的影响.[方法]利用PEG6000溶液模拟干旱胁迫,测定了4个大麦品种地上部分及根系中丙二醛含量以及超氧化物歧化酶(SOD),过氧化物酶(POD)和过氧化氢酶(CAT)活性变化.[结果]参试大麦品种地上部分及根系中丙二醛含量随干早胁迫时间的延长均有不同程度增加,地上部分超氧化物歧化酶、过氧化物酶活性随胁迫时间的延长呈先升高后下降趋势,保护酶活性根系中与地上部分存在差异.品种间也存在差异,表现为抗早品种Tevoel和矮秆早的超氧化物歧化酶和过氧化物酶活性升高较快,进一步胁迫中各酶活性均有不同程度下降,且不抗早品种广麦7号和Cmebc下降幅度较大.[结论]干早胁迫下,超氧化物歧化酶、过氧化物酶和过氧化氢酶活性及丙二醛含量变化可作为大麦抗早筛选的依据.