| 其他摘要 | 菊芋（Helianthus tuberosus L.）又称洋姜，原产北美，为菊科向日葵属植物，能形成地下块茎；园艺学中划归为薯蓣根茎类蔬菜，富含菊糖。菊芋抗寒、耐旱 、耐盐碱，是生物燃料的良好原材料。根据菊芋块茎表皮颜色可分为白皮、红皮和紫皮。本试验通过测定生理指标和运用蛋白质组学方法对耐盐低产的红皮和盐敏感高产的白皮两个菊芋品种进行 250 mM NaCl 处理，希望从中找出耐盐差异性信息，为将来通过分子育种培育耐盐高产新品种和阐明植物耐盐机理提供科学理论依据。盐胁迫对两个菊芋品种整株影响的观察结果表现为红皮比白皮更耐盐，红皮地上部受害症状比白皮轻，但根系受害症状明显比白皮重。 丙二 醛（Malondialdehyde, MDA）含量和相对电导率（Relative electrolyte leakage，REL）的实验结果表明：两个品种根系 MDA 含量上升，并且处理 48 h 时，红皮 MDA含量是白皮的 1.7 倍。两个品种根系的 REL 变化趋势与 MDA 含量变化趋势类似 ，也均表现为上升趋势，处理后期红皮 REL 值也高于白皮。这些结果表明白皮菊芋根系具有更好的耐盐缓冲性。研究发现两者抗氧化酶活性先升后降，但存在明显差别。白皮根系超氧化物歧化酶（Superoxide dismutase activity, SOD）活性峰值出现在 6 h，但红皮则出现在 12 h；最终，红皮和白皮 SOD 活性分别是对照的 96%和 107%。白皮根系过氧化氢酶（Catalase, CAT）活性显著高于红皮；12 h 时，白皮根系 CAT 活性达到峰值，是红皮的 2.47 倍；而红皮 CAT 活性则表现出相对平缓的变化趋势。红皮根系过氧化物酶（Peroxidase, POD）活性在盐处理 6 h 时达到峰值，而白皮 POD活性峰值出现在 24 h，分别为 9.85 U mg -1 protein min -1 and 12.96 U mg -1 proteinmin -1 。红皮根系抗坏血酸过氧化物酶（Ascorbate peroxidase, APX）活性下降大于白皮。与白皮根系抗氧化酶活性相比，这些结果表明红皮根系受害更重。钾（K+） 钠 （ Na+）离子含量研究结果表明，两个品种地上部 K+含量升高，而根系中下降。白皮根系 K+含量显著高于红皮，进一步表明红皮根系受害较重。两者地上部和根系中 Na+含量均升高，而 K+/Na+比率降低。与红皮相比，白皮地上部 Na+含量较高而 K+/Na+比率较低。因此，可能对叶片光合作用产生伤害并进一步影响整株植物，这或许是白皮对盐敏感的原因之一，但仍需测定地上部指标来进一步确认这种推断。两者根系蛋白质组学分析表明， R.根系大约有 700 多个可重复出现的蛋白cv.点。盐处理过程中，共 104 个蛋白点丰度发生 1.5 倍以上变化（显著性统计检验。其P＜0.05） 中 ，54 个蛋白点上调，46 个蛋白点下调，4 个蛋白点为新诱导蛋白点。已鉴定的 20 个蛋白点中，按其功能分为 9 大类：分别为氨基酸代谢相关蛋白（1 个）、碳水化合物代谢相关蛋白（2 个）、细胞骨架组成相关蛋白（1 个 ）、辅酶和盐诱导相关蛋白（1 个）、解毒和植物防御相关蛋白（2 个）、能量相关蛋白（4 个）、蛋白代谢相关蛋白（5 个）、信号转导相关蛋白（2 个）、未知功能 蛋。白（2 个 ） cv. W.根系大约有 800 多个可重复出现蛋白点。盐胁迫下，共 85 个蛋白点丰度发生 1.5 倍以上变化（显著性统计检验 P＜0.05） 中 ，35 个蛋白点。其上调，44 个蛋白点下调，6 个蛋白点为新诱导蛋白点。已鉴定的 20 个蛋白点中，按其功能分为 6 大类：分别为碳水化合物代谢相关蛋白（5 个）、辅酶和细胞代谢相关蛋白（1 个）、解毒和抗氧化相关蛋白（7 个）、蛋白代谢相关蛋白（3 个）、信号转导相关蛋白（1 个）、未知功能蛋白（3 个 ）。; Helianthus tuberosus L. originates in North America, for the Asteraceae Helianthus species. It can form underground tubers which are rich in inulin, and it is classified as category of tuber and tuberous rooted vegetables in horticulture. Jerusalem artichoke is tolerant to cold, drought, salinity, etc. And its tuber is a good raw material for biofuels. Tubers are divided into White, Red and Purple according to the tuber skin colors of Jerusalem artichoke. In the present study, red skin (low-yield and salt-tolerant) and white skin (high-yield and salt-sensitive) cultivars of Jerusalem artichoke with 250 mM NaCl treatment were compared for salt-tolerant differences by measuring physiological indicators and performing proteome analysis, hoping to obtain the difference information in salt tolerance. Based on the idea, people can breed new high-yield and salt-tolerant cultivars by a molecular means in future, and elucidate the mechanism of plant salt tolerance to further provide scientific theoretical basis.The whole observation with effects of salt stress on two varieties of Jerusalem artichoke showed red skin was more salt-tolerant than white skin. The aboveground victim symptoms of red skin were lighter than that of white skin; however, roots were in an opposite direction. The experimental results of Malondialdehyde (MDA) content and relative electrolyte leakage (REL) indicated that MDA contents in roots of two genotypes increased, but MDA content of red skin was 1.7-fold higher than white skin at 48 h. The trend of REL was a similar to MDA, in other words, also showed an upward trend. The REL of red skin was greater than white skin in the last stage. The results suggested that roots of Jerusalem artichoke tubers with white skin had a better salt-tolerant buffer capacity.Antioxidant enzymes activities in roots of two varieties increased first and then decreased, but obvious differences existed. The peak of superoxide dismutase activity (SOD) of white skin was observed at 6 h, but the maximum of red skin appeared at 12 h. Finally SOD activity was 107% and 96% as compared to normal controls, respectively. Catalase (CAT) activity of white skin was significantly greater than the value of red skin and the summit of the former was 2.47-fold of the latter at 12 h, and the latter showed a moderate trend. Peroxidase (POD) activity of red skin obtained the maximum at 6 h, whereas the peak of white skin displayed at 24 h, 9.85 U mg -1 protein min -1 and 12.96 U mg -1 protein min -1, respectively. Ascorbate peroxidase (APX) activity of red skin declined more than that of white skin. The results suggested that salt stress caused more severe damage to roots of red skin compared with that of white skin.The results of potassium (K+) and sodium (Na+) ion contents exhibited that the concentrations of K+ in the aerial parts of the both increased, however, that in roots of two cultivars declined. And K+ in roots of white skin was significantly greater than that of red skin; it further illustrated the reason why roots of red skin suffered more severe damages. Na+ concentrations in the aerial parts and roots of two cultivars increased, whereas K+/Na+ ratio was opposite to Na+. Compared with changes of red skin, Na+ in the aerial parts of white skin was greater and its K+/Na+ ratio was lower. Thus, this probably resulted in some damages to leaf photosynthesis and further affected the entire plant. This was perhaps one of the reasons why the whole plant of white skin was sensitive to salt. Indicators of the aerial parts will be necessary to be measured to further confirm the inference in future.The proteome analysis results of both cultivars indicated that about 700 protein spots could be reproduced repeatedly in roots of cv. R.. In the process of salt treatment, Total 104 protein spots changed more than 1.5-fold in the abundance (P <0.05). Among them, 54 protein spots up-regulated, 46 protein spots down-regulated and 4 protein spots were newly induced. 20 protein spots identified were divided into nine broad categories according to their functions: (1) Amino acid metabolism, (2) Carbohydrate metabolism-related proteins, (3) Cell cytoskeleton organization, (4) Coenzyme and salt-induced proteins, (5) Detoxifying and plant defense, (6) Energy associated proteins, (7) Protein metabolism associated proteins, (8) Signal transduction mechanisms, (9) Function unknown proteins. More than 800 protein spots could be reproduced repeatedly in roots of cv. W.. Total 85 protein spots changed more than 1.5-fold in the abundance (P <0.05). Of them, 35 protein spots up-regulated, 44 protein spots down-regulated and 6 protein spots were newly induced. Identified 20 protein spots were divided into six categories according to their functions: (1) Carbohydrate metabolism associated proteins, (2) Coenzyme and cell metabolic process, (3) Detoxifying and antioxidant, (4) Protein metabolism associated proteins, (5) Signal transduction mechanisms, (6) Function unknown proteins. |
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