几种芳香植物对干旱胁迫的生长和生理响应

[目的]为引种和开发抗旱性芳香植物提供一定的理论依据。[方法]以多种芳香植物为研究对象,探讨植物受到干旱后植株叶片生理指标与形态指标的变化。[结果]在干旱胁迫下,几种芳香植物的生长受到抑制,植株叶片含水量下降,脯氨酸含量升高。复水后,它们都能恢复良好的生长状态。[结论]在不同种类之间,薄荷和丁香罗勒抗旱性最强,缬草抗旱性最弱。     

PEG诱导水分胁迫对柑桔幼苗细胞质膜透性及脯氨酸含量的影响

柑桔叶片相对含水量(RWC)随聚乙二醇(PEG)处理渗透势的降低而依次降低;叶片细胞质膜透性随PEG处理浓度的增加而依次增大;幼苗叶片累积脯氨酸的数量随水分胁迫时间和强度递增。     

Note: Proline — An inducer of resistance against pearl millet downy mildew disease caused by<Emphasis Type="Italic">Sclerospora graminicola</Emphasis>

In an attempt to find a suitable alternative to the otherwise perilous chemical control strategy of disease management, the amino acid proline was evaluated for its efficiency to elicit resistance in pearl millet (Pennisetum glaucum (L.) R. Br.) against downy mildew disease caused bySclerospora graminicola (Sacc.) Schroet both under greenhouse and field conditions. Proline treatment to seeds at 50 mM concentration for 3 h, significantly enhanced the seed germination and seedling vigor of pearl millet in comparison with the control. The same concentration and duration of seed treatment protected the pearl millet plants from downy mildew by offering 58% protection under greenhouse and 67% protection under field conditions. Studies revealed that 3 days were required for proline-treated plants to develop resistance, which was systemic and was sustained throughout the life of the plants. Apart from disease protection, proline was also found effective in enhancing vegetative and reproductive growth of the plants, as evidenced by the increase in height, fresh weight, leaf area, tillering capacity, 1000-seed weight and grain yield in comparison with the control plants. http://www.phytoparasitica.org posting Oct. 3, 2004.     

香木莲对短时低温胁迫处理的生理生态响应

通过测定木兰科植物香木莲在人为短时低温处理下的一些生理生化指标的变化情况,可以分析香木莲苗木的抗性生理情况,以期对香木莲的抗寒性进行评价.实验结果表明,香木莲的叶片在经短时低温处理后,其脯氨酸含量、丙二醛含量及相对电导率均表现为不同程度的上升.而叶片的叶绿素荧光指数的变化则表现为随处理时间的延长,叶片的原初荧光(Fo)上升,其光化学效率(Fv/Fm)及可变荧光/原初荧光比率(Fv/Fo)则表现为随处理时间的延长而降低.这表明,短时低温处理对叶片的叶绿体光系统的潜在活性及量子传递效率造成了一定的影响,结合生理生化指标的变化,可以部分解释香木莲抗寒机制.     

干旱胁迫下小麦幼苗蛋白质和脯氨酸含量分析

为研究干旱胁迫下小麦幼苗蛋白质和脯氨酸含量变化,进而探明不同品种小麦抗旱性差异,采用15％ PEG-6000渗透胁迫,检测20个小麦品种幼苗蛋白质和脯氨酸含量.结果表明,渗透胁迫下,不同品种小麦幼苗蛋白质含量对照组均高于15％ PEG处理组,品种间蛋白质含量变化率差异较大;不同品种小麦幼苗处理组脯氨酸含量均高于对照组,品种间脯氨酸含量变化率差异也较大;不同品种间处理组与对照组小麦幼苗蛋白质、脯氨酸含量差异均极显著;20个小麦品种中金麦8号、淮麦21和淮麦22具有较强的抗旱性.     

Physiological Responses of Contrasting Rice Genotypes to Salt Stress at Reproductive Stage

Salinity is a major abiotic stress affecting plant growth and productivity. Considerable genetic variation is present in rice in response to salt stress, with higher sensitivity during early seedling and reproductive stage. In this study, physiological changes in leaves and developing panicles of rice genotypes(IR686, Sadri, Rc222, CSR28, IR670 and Pokkali) contrasting in salt tolerance at the reproductive stage were evaluated in greenhouse experiment under salt stress. The results showed that IR670 and the tolerant-check Pokkali maintained lower Na~+/K~+ ratio, less reduction in chlorophyll concentration, lower malondialdehyde(MDA) production, higher concentrations of reduced ascorbate(reduced AsA), higher proline accumulation and lower percentage reduction in pollen viability than the salt-sensitive genotypes under salt stress. The higher concentration of reduced AsA suggests an efficient ROS-scavenging system. Physiological measurements and pollen viability analysis revealed that Sadri(moderately tolerant at the seedling stage) is sensitive to salt stress at the flowering stage. The findings will be useful in breeding salt tolerant varieties at both seedling and reproductive stages by selecting appropriate genotypes and phenotypes.     

铅对黄瓜叶片丙二醛、脯氨酸和可溶性总糖含量的影响

以黄瓜幼苗为材料,进行不同浓度的铅处理,研究其叶片丙二醛、脯氨酸和可溶性总糖含量的变化情况。研究结果表明,黄瓜幼苗叶片丙二醛(MDA)含量与铅浓度呈正相关,梯度Pb2 胁迫造成了幼苗叶片脯氨酸的含量逐渐增多,可溶性总糖含量与对照相比呈先增加后减少的趋势。     

Serum biochemical parameters and amino acids metabolism are altered in piglets by early-weaning and proline and putrescine supplementations

The study was to investigate the effect of early-weaning stress and proline (Pro) and putrescine (Put) supplementations on serum biochemical parameters and amino acids (AA) metabolism in suckling and post-weaning pigs. Blood and small intestinal mucosa were harvested from suckling piglets at 1, 7, 14, and 21 d of age and piglets on d 1, 3, 5, and 7 after weaning at 14 d of age, as well as from piglets received oral administration of Pro and Put from 1 to 14 d old. In suckling piglets, the serum glucose, albumin and total cholesterol levels were increased (P < 0.05) with increasing age, whereas the serum globulin, urea nitrogen (BUN), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) levels were lowered (P < 0.05). The concentrations of most serum AA and the AA transporters related gene expressions were highest in 7-d-old piglets (P < 0.05), whereas the phosphorylation status of the mammalian target of the rapamycin (mTOR) signaling pathway in the small intestine increased in piglets from 1 to 21 d old (P < 0.05). Weaning at 14 d old increased (P < 0.05) the BUN and triglycerides levels in serum, as well as jejunal solute carrier family 7 member 6 (SLC7A6), ileal SLC36A1 and SLC1A1 mRNA abundances at d 1 or 3 post-weaning. Weaning also inhibited (P < 0.05) the phosphorylation levels of mTOR and its downstream ribosomal protein S6 kinase 1 (S6K1) and 4E-binding protein-1 (4EBP1) in the small intestine of weanling pigs. Oral administration of Put and Pro decreased (P < 0.05) serum ALP levels and increased (P < 0.05) intestinal SLC36A1 and SLC1A1 mRNA abundances and mTOR pathway phosphorylation levels in post-weaning pigs. Pro but not Put treatment enhanced (P < 0.05) serum Pro, arginine (Arg) and glutamine (Gln) concentrations of weaning-pigs. These findings indicated that early-weaning dramatically altered the biochemical blood metabolites, AA profile and intestinal mTOR pathway activity, and Pro and Put supplementations improved the AA metabolism and transportation as well as activated the intestinal mTOR pathway in weanling-pigs. Our study has an important implication for the broad application of Pro and Put in the weaning transition of piglets.     

铅胁迫对玉米种子萌发及叶片渗透调节物质含量的影响

采用水培方法,研究铅胁迫对玉米种子萌发及叶片渗透调节物质含量的影响。结果表明:铅对玉米种子萌发率有低浓度的促进效应和高浓度的抑制效应。Pb2+浓度较低时,不影响玉米种子的发芽指数,随着Pb2+浓度的提高,发芽指数逐渐降低。种子的活力指数与发芽势均随着Pb2+浓度的提高而逐渐降低。随着Pb2+浓度的增加,叶片内的可溶性糖和脯氨酸含量均显著增加。     

盐胁迫对菊苣幼苗脯氨酸积累及其代谢途径的影响

以菊苣(Cichorium intybus L.)为材料,研究不同浓度NaCl处理对菊苣幼苗体内脯氨酸代谢的影响,以期揭示菊苣中脯氨酸代谢的基本规律。结果表明:随着处理浓度的增加,菊苣中鸟氨酸δ-氨基转移酶(δ-OAT)活性呈上升趋势;吡咯啉-5-羧酸合成酶(P5CS)活性呈现先升后降的趋势;脯氨酸脱氢酶(ProDH)活性呈下降趋势;而脯氨酸含量则显著上升(P<0.05),但高浓度长时间处理后略有降低。研究表明,NaCl胁迫下谷氨酸(Glu)途径和鸟氨酸(Orn)途径对菊苣中脯氨酸的积累均有贡献,低浓度胁迫时P5CS起关键作用的Glu途径占主导地位,高浓度胁迫时δ-OAT起关键作用的Orn途径占主导地位。