交替灌溉对山黧豆叶片气体交换和土壤水分以及产量指标的影响

改变土壤根系的分布以汲取深层土壤水分的能力是植物避免干旱的主要策略。山黧豆是一种抗逆性强的豆类作物,该研究通过起垄条播控制性沟灌的方式,设置传统灌溉(FI)、交替灌溉(PRD,灌水量减少50%)和不灌溉(NI)3种处理模式,探索不同灌溉模式对播种后不同时期山黧豆土壤水分、根系分布、叶片气体交换、水分利用效率和籽粒产量的影响。结果表明：(1)在FI、PRD和NI处理下,山黧豆的根系分别有89.8%、86.9%和84.9%生长在0~20 cm的表层土壤中;干旱胁迫使PRD和NI处理下深层土壤中根系的比例提高至13.05%和15.07%。(2)在整个生育期内,土壤干旱显著降低了山黧豆叶片的净光合速率、蒸腾速率和气孔导度;在种植后60 d时,PRD和NI处理下叶片的瞬时水分利用效率分别较FI处理显著提高了21.4%和14.9%。(3)干旱胁迫显著降低了山黧豆植株高度、第一豆荚高、平均结荚数和豆粒数以及地上部和根系的干重,但显著增加了根冠比;PRD处理对豆荚长度、豆荚重和每荚豆粒重没有显著影响;PRD和NI处理下山黧豆平均籽粒产量分别比FI处理显著降低了53%和63%。研究发现,在干旱胁迫条件下,山黧豆能够通过提高深层土壤中根系的比例、更多吸收深层土壤水分、显著增加根冠比以及显著提高生殖生长期叶片的瞬时水分利用效率,减轻干旱胁迫对自身生长的影响。该研究结果可为山黧豆在旱区推广种植提供理论依据。     

山黧豆160年研究历程及进展

在全球范围内曾多次发生因过量食用山黧豆导致神经中毒事件,使得国内外对于山黧豆的种植和利用存在一定的误解和偏见,山黧豆的优良农艺价值和潜在功能食品利用价值也受到一定限制。但山黧豆适应性强、分布范围广,是全球气候变化条件下农业可持续发展和地力维持的优选作物,在食品安全、生态文明建设和乡村振兴新形势下,进一步研究和挖掘利用这一古老的优良作物具有重要的战略意义。山黧豆相关研究报道可追溯到1861年,距今已有160年的历史。在同行学者的不懈努力下,山黧豆基础研究及种质资源利用等方面均取得了显著的阶段性成果。该文系统回顾了山黧豆研究160年以来的发展历程,依托历史文献进行了梳理和分析。首先,基于山黧豆神经活性物质β ODAP的分离和鉴定、神经山黧豆中毒机制的探索、β ODAP生物合成途径解析等重要研究节点将整个山黧豆研究进程划分为山黧豆中毒因素的探索、神经山黧豆中毒机理解析和神经山黧豆中毒及β ODAP生物学功能的再认识等三个阶段。其次,总结了山黧豆在毒理学研究、种质资源利用、品质改良基础研究等方面取得的重要进展。特别是以兰州大学为代表的中国学者在β ODAP的分析检测、生物合成途径、山黧豆生理生态学研究及种质资源利用等方面进行了深入探讨,确立了中国在国际山黧豆研究中的主流地位。最后,针对目前山黧豆分子生物学基础研究相对滞后、种质资源缺乏系统利用等问题进行了展望,提出了未来的重点发展方向,为山黧豆种质资源的进一步深入挖掘和应用提供参考。     

60Coγ射线与EMS复合处理对山黧豆抗氧化酶活力及ODAP含量的影响

1　引　　言山黧豆抗寒、抗旱、耐贫瘠 ,尤其适于干旱、半干旱地区种植 .但山黧豆中含有的毒素 β ＯＤＡＰ会导致下肢瘫痪 .由于这个原因限制了山黧豆的大面积栽培 .我们采用 60 Ｃｏγ射线和ＥＭＳ单因子、复因子诱变的方法选育丰产、低毒、无毒山黧豆新品系 .近年来对生物辐射敏感性的研究表明 ,其抗性除与本身ＤＮＡ损伤修复能力有关外 ,还与体内所含防护物质有关 ,ＳＯＤ、ＰＯＤ、ＣＡＴ即是重要的保护物质 .关于抗氧化酶活性与辐射剂量、诱变剂浓度关系的研究很少 ,因此本实验对山黧豆成苗率、抗氧化酶活性、和 β ＯＤＡＰ含量进行…     

山黧豆毒素β-ODAP的生态学功能及应用

山黧豆是一种具有广谱抗逆性且营养丰富的豆科作物,但其含有β-N-草酰-L-α,β-二氨基丙氨酸(β-N-oxalyl-L-α,β-diaminopropionic acid, β-ODAP)神经毒素,人畜长期大量食用会导致神经性中毒,因此限制了山黧豆种质资源的利用.本文综述了干旱胁迫下山黧豆毒素β-ODAP对植株渗透调节和生长调节的影响,以及β-ODAP的分析方法、毒理机理和实用价值方面的研究进展,并对低毒和无毒品种选育策略进行了总结.干旱胁迫下,山黧豆合成大量毒素β-ODAP,其含量随胁迫程度增强而逐渐升高.β-ODAP可为植株生长和种子发育提供氮源,并积极参与清除活性氧过程,作为小分子可溶性氨基酸参与渗透调节,作为锌离子转运体参与根瘤发育.而含硫氨基酸(甲硫氨酸和半胱氨酸)含量升高可使山黧豆毒性显著降低.近年来,在山黧豆种质资源收集、杂交育种,以及通过组织培养和基因操作等技术进行低毒或无毒山黧豆品种选育方面做了大量工作.β-ODAP可通过破坏细胞内Ca²⁺稳态和作为谷氨酸类似物引发兴奋性中毒,但在止血和抗肿瘤等方面有重要的药用价值.     

山黧豆根系对H2O2诱导氧化胁迫的生理应答

以水培7d苗龄的山黧豆幼苗为材料,向水培溶液中施加不同浓度H2O2处理山黧豆幼苗24h,分析山黧豆根系受氧化胁迫的程度与抗氧化系统的应答特征,以揭示山黧豆对氧化胁迫的耐受机制。结果显示:(1)随外源H2O2处理浓度的不断增加,山黧豆幼苗侧根的数目无显著变化,而其根的鲜重则显著降低。(2)同时,根系组织的内源H2O2染色范围和程度显著增高,但根尖区域始终保持较低水平的H2O2;相反,O-·2染色范围和程度明显减少,根尖区域却始终保持较高水平的O-·2。(3)同期根系抗坏血酸(ASC)含量及过氧化氢酶(CAT)、过氧化物酶(POD)与抗坏血酸过氧化物酶(APX)的活性均表现出了先升高后降低的趋势,而超氧化物歧化酶(SOD)一直表现为持续上升的趋势。研究表明,在外源H2O2胁迫条件下,山黧豆根系O-·2的积累可能与其生长和活力呈正相关,而根系H2O2的积累则与其受氧化胁迫程度呈正相关;低浓度的H2O2处理可以提高山黧豆抗氧化系统对体内活性氧的清除能力。     

山黧豆叶片蛋白质双向电泳技术的建立

以山黧豆叶片为材料,比较分析了蛋白质的不同提取方法,在此基础上着重于样品制备。对IPG胶条的选择,第一向等电聚焦和第二向SDS-聚丙烯酰胺凝胶电泳的电泳程序及参数、染色方法等相关技术进行了比较和条件优化。结果显示：采用TCA-丙酮沉淀法提取蛋白质,裂解液中加入Tris-base作为蛋白酶抑制剂,等电聚焦电泳时延长低电压的电泳时间（30V、12h,500V、1h,1000V、2h）以促进盐离子泳出的方法对山黧豆叶片蛋白质进行双向电泳,并用考马斯亮蓝和银染复合染色法进行凝胶染色,能够获得蛋白点清晰的双向电泳图谱,说明用优化后的方法建立起的山黧豆叶片蛋白质双向电泳技术,蛋白质样品制备质量好,电泳分辨率高,完全适合于进一步的蛋白质组学研究。     

山黧豆(Lathyrus sativus L.)苗菜用品种的筛选与评价

针对山黧豆苗菜用特性评价体系不完善和优良品种鉴别不明确的现状,收集我国不同地区的29份山黧豆品种资源作为供试材料,模拟中农绿谷芽苗菜研究院山黧豆苗的培育工艺与条件,根据山黧豆及山黧豆苗的8项性状指标,采用基本统计量分析、K-均值聚类分析和相关性分析对山黧豆苗菜用特性进行初步评价。结果表明,各性状中苗菜产出量的变异最大,变异系数为24.42%。29份山黧豆品种资源可划分为5个类群。其中一类具有小粒、高苗菜产出量、高可溶性蛋白含量、高VC含量的特征。苗长与苗菜产出量和种皮的光滑程度极显著正相关;苗菜产出量与品种种皮光滑程度极显著正相关,与百粒重显著负相关。本研究显示,鉴定与评价山黧豆品种苗菜用特性优劣时,应重点考虑苗菜产出量并兼顾营养品质和感官品质,优先筛选苗菜产出量≥1.01的品种作为芽用备选资源。初步筛选出甘肃张掖山黧豆、白香山黧豆、阿杂山黧豆-2共3份优异资源,供进一步研究。     

家山黧豆及其毒素ODAP的研究

家山黧豆作为人类的食物及动物的饲料,最早可追溯到新石器时代。长期以来,因其营养丰富,具有耐旱、耐寒等优良生产性状,广受世界各地的青睐。特别是在大旱年份,在其它粮食作物绝收的情况下,仍有较好的收成,因此,被视为干旱及半干旱地区首选的优良作物。但由于其含有毒素β-ODAP,使山黧豆的种植受到限制。近年来,由于人类对肉质品的量与质的多元化的需求,家山黧豆这一潜在的、丰产的、高营养的豆科作物,已引起各国学者的广泛关注。从家山黧豆在植物学、遗传学、分子生物学、生态学、营养学、山黧豆中毒、毒理学、毒素ODAP、ODAP的分析方法、ODAP的生物合成途径、养殖业等几个方面的研究进展作了简要综述。     

山黧豆及其神经毒素(ODAP)的研究进展

山黧豆具有耐寒、耐旱等优良生产性状，且营养丰富，在恶劣的天气条件下仍能维持较高的产量，因此它是半干旱地区的潜在粮食作物。但长期食用山黧豆会引起中毒，这是由于山黧豆中含有的神经毒素（ＯＤＡＰ）所致，因此筛选无毒品系具有重要意义。本文对山黧豆神经毒素（ＯＤＡＰ）的生物合成毒素异构化等方面作简要综述。     

水分胁迫下山黧豆多胺代谢与β—N—草酰—L—α,β—二氨基丙酸？…

为了研究水分胁迫下山黧豆（Ｌａｔｈｙｒｕｓ ｓａｔｉｖｕｓ Ｌ．）叶片中多胺代谢与β－Ｎ－草酰－Ｌ－α,β－二氨基丙酸（ＯＤＡＰ）积累的相关关系,利用聚乙二醇（ＰＥＧ）对山黧豆幼苗进行水分胁迫处理,同时加入腐胺（Ｐｕｔ）,α－二氟甲基精氨酸（ＤＦＭＡ）和Ｐｕｔ＋ＤＦＭＡ。实验结果表明,随ＰＥＧ处理时间的延长,山黧豆幼苗叶片中Ｐｕｔ、亚精胺（Ｓｐｄ）和精胺（Ｓｐｍ）含量逐渐增加,特别是Ｓｐｍ含量增加     

A high-efficiency,two-dimensional gel electrophoresis platform for mature leaves of grass pea (<Emphasis Type="Italic">Lathyrus sativus</Emphasis> L.)

Grass pea (Lathyrus sativus L.) is the most drought-tolerant legume crop rich in dietary protein. However, little is known about the molecular mechanisms of its drought resistance. Two-dimensional gel electrophoresis (2-DE) is an important experiment technique in proteomics, which has been applied extensively in studies on plant resistance to abiotic stress. To establish an effective 2-DE platform and further study the drought-resistance mechanisms of grass pea using proteomic approaches, three protein extraction methods, different isoelectric focusing (IEF) conditions and various types of gel strips were evaluated using mature leaves. The results showed that the trichloroacetic acid (TCA)/acetone protein extraction method, extending time at low voltage for IEF and using 18 cm gel strip with pH 4.0–7.0 were optimum conditions for 2-DE analysis of grass pea leaves. Applying these optimized 2-DE conditions, 1,481 total protein spots were detected in control leaves and 1,346 spots in polyethylene glycol -treated leaves, of which 67 differentially expressed protein spots were obtained relative to the control. These data suggested that an efficient 2-DE platform with high repeatability and resolution for grass pea mature leaves had been established for the first time here, which could be further used to investigate the drought-resistance molecular mechanisms of grass pea.     

The hyperhydricity ofin vitroregenerants of grass pea (Lathyrus sativus L.) is linked with an abnormal DNA content

The grass pea (Lathyrus sativus) is a wild relative of the protein pea which may be a useful genetic resource for the acquisition of interesting stress resistance traits. However, grass pea is cross incompatible with pea, leaving protoplast fusion as the only alternative to produce interspecific hybrids of grass pea and pea. In addition, as all grass pea seeds contain a toxic aminoacid, low-toxin containing genotypes will have to be produced by gene transfer. In this context, it is therefore essential that regenerated plants are fertile, true-to-type and not chimaeric in nature when they have been obtained in absence of any selection treatment. In the present study, shoot buds were regenerated from hypocotyls of three grass pea genotypes, and flow cytometry permitted us to characterise them in terms of nuclear DNA content. Plant regeneration competence was genotype-dependent and strongly also was correlated with a normal DNA content. The auxin/cytokinin balance of regeneration media affected the DNA level of regenerants. In turn, an abnormal DNA content was systematically associated with severe hyperhydricity symptoms, which hampered the regeneration of rooted, fertile plants.     

Challenges in pea breeding for tolerance to drought: Status and prospects

Drought is increasingly frequent in the context of climate change and is considered a major constraint for crop yield. Water scarcity can impair growth, disturb plant water relations and reduce water use efficiency. Pea (Pisum sativum) is a temperate grain legume rich in protein, fibre, micronutrients and bioactive compounds that can benefit human health. In reducing pea yield because of drought, the intensity and duration of stress are critical. This review describes several drought resistance mechanisms in pea based on morphology, physiology and biochemical changes during/after the water deficit period. Drought tolerance of pea can be managed by adopting strategies such as screening, breeding and marker-assisted selection. Therefore, various biotechnological approaches have led to the development of drought-tolerant pea cultivars. Finally, the main objective of the current research is to point out some useful traits for drought tolerance in peas and also, mention the methods that can be useful for future studies and breeding programmes.     

Molecular Improvement of Tropical Maize for Drought Stress Tolerance in Sub-Saharan Africa

The C4 grass Zea mays (maize or corn) is the third most important food crop globally after wheat and rice in terms of production and the second most widespread genetically modified (GM) crop, after soybean. Its demand is predicted to increase by 45% by the year 2020. In sub-Saharan Africa, tropical maize has traditionally been the main staple of the diet, 95% of the maize grown is consumed directly as human food and as an important source of income for the resource—poor rural population. However, its growth, development and production are greatly affected by environmental stresses such as drought and salinization. In this respect, food security in tropical sub-Saharan Africa is increasingly dependent on continuous improvement of tropical maize through conventional breeding involving improved germplasm, greater input of fertilizers, irrigation, and production of two or more crops per year on the same piece of land. Integration of advances in biotechnology, genomic research, and molecular marker applications with conventional plant breeding practices opens tremendous avenues for genetic modifications and fundamental research in tropical maize. The ability to transfer genes into this agronomically important crop might enable improvement of the species with respect to enhanced characteristics, such as enriched nutritional quality, high yield, resistance to herbicides, diseases, viruses, and insects, and tolerance to drought, salt, and flooding. These improvements in tropical maize will ultimately enhance global food production and human health. Molecular approaches to modulate drought stress tolerance are discussed for sub-Saharan Africa, but widely applicable to other tropical genotypes in Central and Latin America. This review highlights abiotic constraints that affect growth, development and production of tropical maize and subsequently focuses on the mechanisms that regulate drought stress tolerance in maize. Biotechnological approaches to manage abiotic stress tolerance in maize will be discussed. The current status of tropical maize transformation using Agrobacterium as a vehicle for DNA transfer is emphasized. This review also addresses the present status of genetically modified organisms (GMOs) regulation in sub-Saharan Africa.     

Antioxidative Responses and Morpho-anatomical Alterations for Coping with Flood-Induced Hypoxic Stress in Grass Pea (<Emphasis Type="Italic">Lathyrus sativus</Emphasis> L.) in Comparison with Pea (<Emphasis Type="Italic">Pisum sativum</Emphasis>)

Flooding stress constrains crop growth and yield because most agricultural species are flood-sensitive. However, many of the plant species that live in permanently or temporarily flooded habitats have evolved specific traits to cope with these harsh conditions. Grass pea (Lathyrus sativus L.) is a legume that tolerates stresses such as drought, diseases, and pests; however, it is unclear whether grass pea has a tolerance mechanism for flooding stress. To understand if grass pea tolerates hypoxia and how it deals with hypoxic stress, the effects of hypoxia on root tip death, physiological, and morpho-anatomical alterations in grass pea and pea (Pisum sativum), which is sensitive to hypoxia, were compared. The results showed that activities of antioxidant enzymes, namely superoxide dismutase, catalase, ascorbate peroxidase, and glutathione content in grass pea were greater than in pea during hypoxia, which protected the root tip from oxidative damage and reduced ion leakage, which helped maintain membrane integrity. Furthermore, aerenchyma and lateral root development accompanied by ethylene production, moderate ROS accumulation-mediated cell death, and Ca²⁺ spatial-temporal heterogeneity developed well in grass pea compared to pea, which may not only facilitate internal gas diffusion but also promote removal of toxic by-products under hypoxic conditions. These results demonstrate that grass pea is more tolerant to hypoxic stress induced by flooding than garden pea seedlings. This discovery not only provides significant information for understanding the hypoxia-tolerant mechanisms in plants, but also promotes the usability of grass pea in flood-prone areas.     

Physiological responses of groundnut (Arachis hypogea L.) to drought stress and its amelioration: a critical review

Groundnut (Arachis hypogea L.), is an important legume cash crop for the tropical farmers and its seeds contain high amounts of edible oil (43–55%) and protein (25–28%). Even though it is a fairly drought-tolerant, production fluctuates considerably as a result of rainfall variability. To develop a water stress response function in groundnut, research works have been done to improve the performance under varying degrees of stress at various physiological stages of crop growth. This review summarizes recent information on drought resistance characteristics of groundnut with a view toward developing appropriate genetic enhancement strategies for water-limited environments. It is suggested that there are considerable gains to be made in increasing yield and stabilizing the yield in environments characterized by terminal drought stress and by shortening crop duration. Many traits conferring dehydration avoidance and dehydration tolerance are available, but integrated traits, expressing at a high level of organization are suggested to be more useful in crop improvement programs. Possible genetic improvement strategies are outlined, ranging from empirical selection for yield in drought environments to a physiological–genetic approach. It was also suggested that in view of recent advances in understanding drought resistance mechanisms, the later strategy is becoming more feasible. It is summarized that application of knowledge into practice in a systematic manner can lead to significant gains in yield and yield stability of the worlds groundnuts production. Research is needed to develop transferable technology to help farmers of arid and semi-arid regions. Increasing soil moisture storage by soil profile management and nutrient management for quick recovery from drought are some of the areas that need to be explored further.     

Label‐free quantitative proteomic analysis of tolerance to drought in Pisum sativum

Abiotic stresses caused by adverse environmental conditions are responsible for heavy economic losses on pea crop, being drought one of the most important abiotic constraints. Development of pea cultivars well adapted to dry conditions has been one of the major tasks in breeding programs. The increasing food requirements drive the necessity to broaden the molecular basis of tolerance to drought to develop pea cultivars well adapted to dry conditions. We have used a shotgun proteomic approach (nLC‐MSMS) to study the tolerance to drought in three pea genotypes that were selected based on differences in the level of water deficit tolerance. Multivariate statistical analysis of data unraveled 367 significant differences of 700 identified when genotypes and/or treatment were compared. More than half of the significantly changed proteins belong to primary metabolism and protein regulation categories. We propose different mechanisms to cope drought in the genotypes studied. Maintenance of the primary metabolism and protein protection seems a strategy for drought tolerance. On the other hand susceptibility might be related to maintenance of the homeostatic equilibrium, a very energy consuming process. Data are available via ProteomeXchange with identifier PXD004587.     

Transgenic Plants of Creeping Bent Grass Harboring the Stress Inducible Gene, 9-cis-epoxycarotenoid dioxygenase, are Highly Tolerant to Drought and NaCl Stress

Transgenic lines of creeping bent grass were generated by Agrobacterium-mediated transformation with the VuNCED1 which was cloned from cow pea has a homology to 9-cis-epoxycarotenoid dioxygenase, which is supposed to be involved in abscisic acid (ABA) biosynthesis. ABA, a cleavage product of carotenoids, is involved in stress responses in plants. The limiting step of ABA biosynthesis in plants is presumably the cleavage of 9-cis-epoxycarotenoids, the first committed step of ABA biosynthesis. Molecular analyses of transgenic lines as performed by Southern hybridization genomic DNA-PCR revealed integration of the VuNCED1. Challenge studies performed with transgenic plants by exposure to salt stress (up to 10 dS m⁻¹) and water stress (up to 75%) for 10 weeks, revealed that more than 50% of the transgenic plants could survive NaCl and drought stress whereas wild-type was not. ABA levels were measured under drought and normal conditions, endogenous ABA was dramatically increased by drought and NaCl stress in transgenic plants. These results indicate that it is possible to manipulate ABA levels in plants by over expressing the key regulatory gene in ABA biosynthesis and that stress tolerance can be improved by increasing ABA levels. Chenna Reddy Aswath and Sun Hyung Kim - First two authors contributed equally to this work