北柴胡不定根培养及茉莉酸甲酯处理对柴胡皂苷含量的影响

目的:建立北柴胡不定根培养体系,明确茉莉酸甲酯(MeJA)处理对北柴胡不定根中柴胡皂苷含量积累的影响。方法:利用固体和液体相结合的组织培养技术培养北柴胡不定根;分别以不同浓度的MeJA处理不定根不同时间,利用HPLC测定处理后不定根中柴胡皂苷含量的积累变化。结果:培养了北柴胡不定根;MeJA处理对北柴胡不定根中柴胡皂苷含量的积累有明显促进作用,当MeJA浓度为200μmol/L时,柴胡皂苷含量最高,为0.45%;以200μmol/L MeJA处理北柴胡不定根26 d时,柴胡皂苷含量最高,为0.51%。结论:北柴胡不定根培养结合MeJA诱导,可做为柴胡皂苷次生代谢合成途径及其积累规律研究的有效技术体系。     

茉莉酸甲酯对水稻幼苗生长的影响

２．５×１０＾－７ｍｏｌ·Ｌ＾－１茉莉酸甲酯促进水稻幼苗生长,而高于２．５×１０＾－５ｍｏｌ·Ｌ＾－１则抑制。不同水稻品种对茉莉酸甲酯的反应不同。     

外源茉莉酸甲酯对非生物胁迫下蝴蝶兰幼苗叶绿素荧光和抗氧化指标的影响

通过盆栽试验,研究了外源茉莉酸甲酯（MeJA）处理对低温、干旱和极端高温胁迫下蝴蝶兰幼苗叶绿素荧光参数和抗氧化指标的影响。结果表明,较高浓度的MeJA（150和200μmol·L-1）提高了非生物胁迫下蝴蝶兰幼苗叶片最大光化学效率（Fv/Fm）和实际光化学效率（ΦPSII）,降低了叶片相对电导率,还使得超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）活性升高,丙二醛（MDA）含量降低。表明MeJA作为一种生物调节剂,一定浓度的处理对蝴蝶兰幼苗抗逆性的提高具有明显效果。     

茉莉酸甲酯对烟草幼苗抗炭宜病的影响

本文探讨了茉莉酸甲酯（ＭＪ）对烟草幼苗抗炭疽病（由毁灭性刺盘孢引起）的影响。不同品种烟草抵抗毁灭性刺盘孢孢子侵染的能力不同,“巴西”品种的抗性强,“Ｋ３２６”品种抗性弱,“广黄５５”品种抗生居中。ＭＪ处理烟草幼苗后,可以减轻幼苗炭宜病的发病程度;同时烟草幼苗的病原相关蛋白含量有所提高,但只有“巴西”烟草的ＰＲ蛋白含量与抗病显著正相关。     

茉莉酸甲酯对花生幼苗各器官中碳水化合物含量影响的研究

茉莉酸甲酯对花生幼苗各器官中碳水化合物含量影响的研究江月玲，潘瑞炽（广州师范学院生物系，广州５１０４００）（华南师范大学生物系，广州５１０６３１）ＳＴＵＤＩＥＳＯＦＴＨＥＥＦＦＥＣＴＯＦＭＥＴＨＹＪＡＳＭＯＮＡＴＥＯＮＴＨＥＣＡＲＢＯＨＹＤＲＡＴＥＣ...     

茉莉酸甲酯对水稻幼苗光合作用的影响

２．５×１０－４ｍｏｌ／Ｌ茉莉酸甲酯处理水稻（ＯｒｙｚａｓａｔｉｖａＬ．）幼苗叶片,可明显地降低Ｃｈｌａ、Ｃｈｌｂ的含量及叶片的光合速率,抑制ＲｕＢＰＣａｓｅ的活性,抑制幼苗叶片中ＲｕｂｉｓＣＯ大亚基的合成,降低小亚基的含量。对幼苗叶片中叶绿素含量、叶片的光合速率及ＲｕＢＰＣａｓｅ的活性没有影响。     

茉莉酸甲酯对水稻幼苗抗冷性的影响

测定茉莉酸甲酯（MJ）对冷胁迫条件下水稻幼苗生长和与抗冷性相关生理生化指标影响的结果表明：较高浓度的MJ（10^-3mol·L^-1）明显抑制冷胁迫下的水稻幼苗生长,增加细胞膜的渗透性;浓度低一些的MJ（10^-4、10^-5、10^-6、10^-7mol·L^-1）对冷胁迫下水稻幼苗的生长和细胞膜有不同程度的保护作用,其中以10～mol·L^-1MJ的效果为佳。10～mol·L^-1 MJ处理的叶中叶绿素降解程度小,可溶性糖、可溶性总蛋白和脯氨酸的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）的活性均增加,丙二醛（MDA）含量降低,因而水稻幼苗的抗冷性提高。     

茉莉酸甲酯对菊花抗蚜性的影响

本研究以杭白菊为试验材料,分析茉莉酸甲酯对菊花抗蚜性的影响。供试幼苗叶面喷施不同浓度(0.01、0.05、0.1、0.5、1 mmol·L^-1)茉莉酸甲酯后接种菊姬长管蚜,测定外源茉莉酸甲酯对蚜虫胁迫下菊花叶片的保护酶、防御酶活性、渗透性物质、次生代谢物和茉莉酸途径关键酶基因表达的影响,探究菊花抗蚜性与茉莉酸信号途径的关系。结果表明: 0.01、0.05、0.1、0.5、1 mmol·L^-1浓度的茉莉酸甲酯均显著提高了杭白菊叶片的保护酶、防御酶活性及次生代谢物含量,降低了丙二醛和可溶性糖含量,外源茉莉酸甲酯处理诱导杭白菊CmAOS和CmCOI1的表达,并使内源茉莉酸含量显著增加,杭白菊的抗蚜性增强。     

外源茉莉酸和茉莉酸甲酯诱导植物抗虫作用及其机理

综述了茉莉酸(jasmonic acid, JA)和茉莉酸甲酯(methyl jasmo nate, MJA)的分子结构和应用其诱导的植物抗虫作用及其机制。植物受外源茉莉酸或茉莉酸甲酯刺激后,一条反应途径是由硬脂酸途径激活防御基因,另一条途径是直接激活防御基因。防御基因激活后导致代谢途径重新配置,并可能诱导植物产生下列4种效应：（1）直接防御,即植物产生对害虫有毒的物质、抗营养和抗消化的酶类,或具驱避性和妨碍行为作用的化合物;（2）间接防御,即产生吸引天敌的挥发物;（3）不防御,即无防御反应;（4）负防御,即产生吸引害虫的挥发物。     

抗茉莉酸甲酯单抗制备及小麦和黑麦草颖花中茉莉酸含量的测定

本文报道了识别茉莉酸甲酯(MeJA)的单克隆抗体的制备。该抗体源于以茉莉酸的C-1位羧基为偶联位点,钥孔娥血蓝蛋白为载体合成的免疫原。该抗体对甲酯化茉莉酸的识别力明显强于对茉莉酸(JA)的;JA分子中戊烯侧链的完整性对该抗体的识别力有很大影响。于该侧链的C-9和C-10位加氢(形成Dihydro-JA),或除去C-12(形成JAS-25),都会大幅度降低该抗体的结合活性。该抗体对亚麻酸、南瓜酸、冠毒素及Theobroxide均无识别力。用该抗体建立了定量检测JA的固相抗体型酶联免疫吸附定量测定法,检测范围为2．06-500 pmol MeJA。并探查了小麦及黑麦草开颖前后颖花的JA含量。发现随着开颖时间的临近,JA含量显著升高;颖花开放时达到最大值,随后急剧下降。     

微波辅助提取木豆根中染料木素工艺

以木豆根为原料,利用微波辅助提取技术进行提取,在单因素实验的基础上对提取条件进行了考察,根据BBD(Box-Behnken design)实验设计原理,采用3因素3水平的响应面分析法,以木豆根中主要异黄酮染料木素(genistein)为指标,对提取过程进行优化,得到最佳工艺参数为：提取温度为68℃,固液比为32∶1 mL·g^-1,乙醇浓度为78%,提取功率700 W,提取时间15 min。在最佳提取条件下染料木素的提取率可达到0.465±0.032 mg·g^-1。本研究对于微波提取技术的应用及木豆根的开发和利用都具有显著的意义。     

木豆毛状根的诱导及其培养条件的研究

利用发根农杆菌LBA9402对木豆叶片直接进行诱导产生毛状根。本实验研究出诱导木豆毛状根的最佳条件是,以木豆叶片为外植体,于1/2MS固体培养基上预培养2~4 d,菌液浓度OD₆₀₀=0.6~0.8,浸染20 min,共培养3 d,诱导率为60.00%。在分子水平用PCR检测表明,发根农杆菌9402Ri质粒上的T-DNA成功整合进木豆毛状根的基因组中。     

碳源、生长素及诱导子对木豆不定根生长和次生代谢产物合成的影响

以1/2MS为基本培养基,研究了蔗糖、IBA、茉莉酸甲酯（MJ）及水杨酸（SA）对木豆不定根生物量和次生代谢产物合成的影响。研究结果表明,蔗糖浓度对木豆不定根的生物量和次生代谢产物合成有显著影响,蔗糖浓度为30 g·L^-1时,木豆不定根的生物量和次生代谢产物的含量均达到最大值。低浓度的IBA有利于木豆不定根的生长和次生代谢产物的积累,高浓度的IBA表现出抑制作用。IBA浓度为0.1 mg·L^-1时,生物量、染料木素及芹菜素含量均为最大值,分别为对照组的1.1、1.1和2.8倍。在0~200 μmol·L^-1浓度范围内,MJ对不定根的生长几乎无影响（P>0.05）,但对次生代谢产物的合成有重要影响。MJ浓度为100 μmol·L^-1时,染料木素和芹菜素的含量均达到最大值,分别为对照组的1.9和2.1倍。SA抑制木豆不定根的生长和染料木素的合成,但对芹菜素的合成有一定促进作用,SA浓度为100 μmol·L^-1时,芹菜素的含量最高,为对照组的1.5倍。木豆不定根的悬浮培养是获得次生代谢产物的一条有效途径,为大规模生产染料木素和芹菜素提供了很好的思路。     

Genetic patterns of domestication in pigeonpea (Cajanus cajan (L.) Millsp.) and wild Cajanus relatives

Pigeonpea (Cajanus cajan) is an annual or short-lived perennial food legume of acute regional importance, providing significant protein to the human diet in less developed regions of Asia and Africa. Due to its narrow genetic base, pigeonpea improvement is increasingly reliant on introgression of valuable traits from wild forms, a practice that would benefit from knowledge of its domestication history and relationships to wild species. Here we use 752 single nucleotide polymorphisms (SNPs) derived from 670 low copy orthologous genes to clarify the evolutionary history of pigeonpea (79 accessions) and its wild relatives (31 accessions). We identified three well-supported lineages that are geographically clustered and congruent with previous nuclear and plastid sequence-based phylogenies. Among all species analyzed Cajanus cajanifolius is the most probable progenitor of cultivated pigeonpea. Multiple lines of evidence suggest recent gene flow between cultivated and non-cultivated forms, as well as historical gene flow between diverged but sympatric species. Evidence supports that primary domestication occurred in India, with a second and more recent nested population bottleneck focused in tropical regions that is the likely consequence of pigeonpea breeding. We find abundant allelic variation and genetic diversity among the wild relatives, with the exception of wild species from Australia for which we report a third bottleneck unrelated to domestication within India. Domesticated C. cajan possess 75% less allelic diversity than the progenitor clade of wild Indian species, indicating a severe "domestication bottleneck" during pigeonpea domestication.     

Comparisons of Earlier- and Later-formed Pods of Pigeonpeas (Cajanus cajan (L.) Millsp.)

On branches of indeterminate cultivars of pigeonpea, floweringbegins at the basal nodes and proceeds acropetally; in morphologicallydeterminate cultivars, flowering begins on the apical racemesand proceeds basipetally. In cultivars of both types, withinthe racemes flowering proceeds acropetally. Under normal conditionsmore pods are set from earlier-formed flowers than from later-formedflowers, many of which are shed. Consequently the earlier-formedpods are found at the more basal nodes of racemes, and in indeterminatecultivars at the more basal nodes on the branches. The averageweight of earlier and later-formed pods, collected from thebasal and apical nodes of the racemes or of the branches, wassimilar; so was the number of seeds per pod, the weight perseed and the nitrogen content of the seeds. This pattern differsfrom that found in most herbaceous legumes, where later-formedpods are smaller, and indicates that pigeonpeas set fewer podsthan they are capable of filling. This behaviour may be relatedto the intrinsically perennial nature of pigeonpeas. The comparisonof the weights of earlier- and later-formed pods could providea simple screening procedure for identifying plants with anannual nature among existing cultivars or in breeders' lines. Cajanus cajan (L.) Millsp., pigeonpea, pod development, seed number, seed weight, nitrogen content     

The Effects of Salinity on Nitrogen Fixation and Trehalose Metabolism in Mycorrhizal Cajanus cajan (L.) Millsp. Plants

Arbuscular mycorrhizal (AM) fungi exist widely in natural ecosystems as well as in salt-affected soils and are considered suitable candidates for bio-amelioration of saline soils. Plants respond to salinity by accumulating sugars and other low-molecular-weight compatible solutes. One such compound is trehalose, which has been found to play an important role as a stress protectant. The aim of the present investigation was to study interactions between an AM fungus and salinity stress on growth, nitrogen fixation, and trehalose metabolism in Cajanus cajan (L.) Millsp. (pigeonpea). Two genotypes [Sel 85N (salt-tolerant) and ICP 13997 (salt-sensitive)] were subjected to saline treatments with and without mycorrhizal inoculations. Salinity reduced plant biomass (shoot and root) in both genotypes and resulted in a decline in shoot-to-root ratio (SRR); however, a smaller decline was observed in Sel 85N than in ICP 13997. AM colonization was reduced with increasing salinity levels but mycorrhizal responsiveness (MR) increased. Genotypic variability in nitrogen fixation and trehalose metabolism in response to salinity and mycorrhization was observed. An increment in nodule number was accompanied by a reduction in dry mass. Subsequently, nodular activity (leghemoglobin, acetylene-reduction activity [ARA], nitrogen content) was reduced under soil salinity, which was more profound in ICP 13997 than in Sel 85N. The symbiotic association with Glomus mosseae led to significant improvement in plant dry mass and nitrogen-fixing potential of nodules under salt stress. Salinity led to an increase in trehalose-6-P synthetase (TPS) and trehalose-6-P phosphatase (TPP) activities resulting in increased trehalose content in nodules, which was accompanied by inhibition of trehalose catabolism (trehalase activity). AM plants had lower trehalase activity under saline and nonsaline conditions. Thus, a symbiotic relationship between plant roots and G. mosseae might have resulted in salinity tolerance in a genotype-dependent manner.     

Plant regeneration in pigeonpea [Cajanus cajan (L.) Millsp.] by organogenesis

A method for regenerating pigeonpea [Cajanus cajan (L.) Millsp.] plants has been developed using distal cotyledonary segments of mature seeds as explants. A large number of shoot buds were induced directly from explants of genotypes T-15-15 and GAUT-82-90 when cultured on six different basal media fortified with 22.2 μm N⁶-benzylaminopurine, 2.3 μm kinetin, and 271 μm adenine sulfate. The shoot buds developed into shoots when they were subcultured on the same medium but with one-tenth concentrations of cytokinins and adenine sulfate. The shoots elongated by subculturing first two to three times on Murashige and Skoog (MS) basal medium supplemented with 2.22 μm N⁶-benzylaminopurine and 0.54 μm α-naphthaleneacetic acid or on half-strength MS medium containing 2.89 μm gibberellic acid, and then once on the same medium without growth regulators. Elongated shoots were rooted with 80–85% efficiency on MS medium with 4.92 μm indole-3-butyric acid and the plantlets were transferred for hardening. Plants survival in pots was 70–75%. This method may be useful for improving the crop through genetic manipulations. Received: 11 August 1997 / Revision received: 12 January 1998 / Accepted: 30 January 1998     

The Influence of Some Phenolic Compounds on Nodulation in Pigeonpea (Cajanus cajan(L.) Millsp.)

Studies on exogenous application of phenolic compoundsviz: p-hydroxybenzoic acid, resorcinol and chlorogenic acid each with concentration of 10^-4 M are done on the legume (Cajanus cajan (L.)Millsp.) AL-15. The effect of applied phenolic compounds as well as of structural differences in phenols indicate a marked influence of phenolic compounds in regulating growth processes in plants. Fresh and dry mass of various plant parts increased after foliar spray with phenols resulting in an improved harvest index. It is seen that phenols also play an important role in the initiation and development of nodules.     

In vitro regeneration and transformation of pigeonpea [Cajanus cajan (L.) Millsp]

A requirement for generating transgenic pigeonpea [Cajanuscajan (L.) Millsp] plants is the development of a highly efficientin vitro regeneration procedure. This goal was achieved byusing germinated seedlings grown on B5 medium supplemented with 10 mgl^–1 6-benzylaminopurine, which induced differentiatingcallus formation in the cotyledonary node region. The calli were transferred onB5 medium with 0.2 mg l^–1 6-benzylaminopurine toobtain shoot induction. Elongated shoots were then further cultured on a B5hormone-free medium for rooting. Using this regeneration system transgenicpigeonpea plants were obtained both by particle bombardment andAgrobacterium tumefaciens-mediated gene transfer. Thepresence of the transgenes in the pigeonpea genome was confirmed by GUS assays,PCR and Southern hybridisation. The transgenic rooted plants were successfullytransferred to soil in the greenhouse. GUS and PCR assays of T1 progeniesconfirmed that the transgenes were stably transmitted to the next generation.This is the first report of successful use ofAgrobacteriumas well as particle bombardment for production of transgenic pigeonpea plants.