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PHILIP W. ATKINSON ALLAN J. BAKER KAREN A. BENNETT NIGEL A. CLARK JACQUIE A. CLARK KIMBERLY B. COLE ANNE DEKINGA AMANDA DEY SIMON GILLINGS PATRICIA M. GONZÁLEZ KEVIN KALASZ CLIVE D. T. MINTON JASON NEWTON LAWRENCE J. NILES THEUNIS PIERSMA ROBERT A. ROBINSON HUMPHREY P. SITTERS 《Journal of Applied Ecology》2007,44(4):885-895
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KAUSHIK GHOSE SANJUKTA DEY HANNAH BARTON GARY J. LOAKE DEBABRATA BASU 《Molecular Plant Pathology》2008,9(6):763-775
The lack of availability of sources of resistance against Alternaria brassicicola within the family Brassicaceae has made oilseed mustard plants a target for one of the most damaging and widespread fungal diseases, Alternaria black spot. Of the other non‐host‐resistant/tolerant plants, Sinapis alba, white mustard, is considered to be the most important apart from Arabidopsis. To understand the defence response of S. alba upon incompatible interaction with this pathogen, a functional genomic approach using cDNA amplified fragment length polymorphism was performed. The highly reproducible bands, found to be either more amplified or uniquely present in infected S. alba plants compared with non‐infected plants, were further subjected to comparative reverse Northern analysis in the incompatible white mustard (S. alba) and compatible India mustard (Brassica juncea L.) plants. The suppression of 46% of the genes in the compatible background indicates the possibility of effective and specific recognition of Alternaria in S. alba. Analysis of the 118 genes up‐regulated specifically in infected S. alba compared with B. juncea showed that 98 genes have similarity to proteins such as receptor‐like protein kinase genes, genes involved with calcium‐mediated signalling and salicylic acid‐dependent genes as well as other genes of known function in Arabidopsis. The apparent expression profile data were further confirmed for selected genes by quantitative real‐time polymerase chain reaction analysis. Classification of these genes on the basis of their induction pattern in Arabidopsis indicates that the expression profile of several of these genes was distinct in S. alba compared with B. juncea. 相似文献
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Changes in Phosphorus Fractions and Phytase Activity of Rice Seeds during Germination 总被引:4,自引:0,他引:4
The present experiment provides information on the phosphorus compounds in rice seeds and elucidates the changes they undergo during germination. In ungerminated seeds, the bulk of total-P appears in phytin (about 76 per cent). It is then dephosphorylated in course of germination with a simultaneous accumulation of large amounts of inorganic-P. Lipid-P increases very rapidly from 0 to 24 hours. The increase up to 72 hours is gradual, after which it drops at 96 hours and again rises to a maximum after 120 hours. The ester-P and RNA-P, fractions increase in concentration with time of germination (except 120 hours). Protein-P begins to fall after 48 hours, while DNA-P remains more or less constant throughout the experiment. The two pH optima recorded for phytase activity at 4.0 and 9.0, suggests that there exist two phytases, one acidic and the other alkaline. Both behave similarly during germination with a continuous increase throughout the course of the experiment. The enzyme with an optimal pH at 4 hydrolyses phytin more actively than the other with the pH optimum at 9.0. Phytase shows maximum activity at a stage when most of the phytin has disappeared; the metabolic significance is uncertain. 相似文献
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Intrasexual competition for reproduction is thought to be an important factor in the evolution of ornaments and weapons in males. However, the evolution of morphologically similar traits in females is often explained through other mechanisms, and the role of intrasexual competition in female trait elaboration has received little attention. Here, we explore the factors associated with female trait elaboration in the cooperatively breeding Pukeko (the New Zealand race of the Purple Swamphen Porphyrio porphyrio melanotus) by comparing sexual dimorphism in an ornament across two populations. Importantly, the two populations considered differ in several social factors that could affect the degree of female–female competition, and could thereby produce differential selection on elaborate female traits. Recent studies have suggested that high reproductive skew (i.e. monopolization of reproduction by dominant individuals) could influence the intensity of intrasexual competition and select for female elaboration. However, we found that sexual dimorphism was diminished and Pukeko females had more elaborate ornaments under conditions of low reproductive skew. We discuss alternative factors that could influence the degree of female–female competition, and show that reproductive skew may not always provide an accurate estimate of the scope for intrasexual competition. 相似文献
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Debjani DEY A. COUMAR 《昆虫学报》2008,51(2):234-236
作者通过电镜观察等手段,发现并确认产于印度的绢毛弓背蚁Camponotus sericeus Fabricius为该属第3个具有后胸腺的物种,揭示了弓背蚁属物种缺乏后胸腺普遍规律基础上的特殊性,对阐明后胸腺在蚂蚁进化过程中的演化趋势和生物学意义具有参考价值。 相似文献
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Block designs with nested rows and columns 总被引:1,自引:0,他引:1
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