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981.
Acid phosphatase role in chickpea/maize intercropping 总被引:7,自引:1,他引:6
Background and aims Organic P comprises 3080 %of the total P in most agricultural soils. It has been proventhat chickpea facilitates P uptake from an organic P sourceby intercropped wheat. In this study, acid phosphatase excretedfrom chickpea roots is quantified and the contribution of acidphosphatase to the facilitation of P uptake by intercroppedmaize receiving phytate is examined. Methods For the first experiment using hydroponics, maize(Zea mays Zhongdan No. 2) and chickpea (Cicerarietinum Sona) were grown in either the sameor separate containers, and P was supplied as phytate, KH2PO4at 0·25 mmol P L1, or not at all. The second experimentinvolved soil culture with three types of root separation betweenthe two species: (1) plastic sheet, (2) nylon mesh, and (3)no barrier. Maize plants were grown in one compartment and chickpeain the other. Phosphorus was supplied as phytate, Ca(H2PO4)2at 50 mg P kg1, or no P added. Key results In the hydroponics study, the total P uptakeby intercropped maize supplied with phytate was 2·1-foldgreater than when it was grown as a monoculture. In the soilexperiment, when supplied with phytate, total P uptake by maizewith mesh barrier and without root barrier was 2·2 and1·5 times, respectively, as much as that with solid barrier.In both experiments, roots of both maize and chickpea suppliedwith phytate and no P secreted more acid phosphatase than thosewith KH2PO4 or Ca(H2PO4)2. However, average acid phosphataseactivity of chickpea roots supplied with phytate was 23-foldas much as maize. Soil acid phosphatase activity in the rhizosphereof chickpea was also significantly higher than maize regardlessof P sources. Conclusions Chickpea can mobilize organic P in both hydroponicand soil cultures, leading to an interspecific facilitationin utilization of organic P in maize/chickpea intercropping. 相似文献
982.
Christian?Carson Jarrod?Robertson Ed?CoeEmail author 《Plant Molecular Biology Reporter》2004,22(2):131-143
Many genes in maize (Zea mays L.) are revealed by mutations that cause phenotypic variation from normal. These mutants are valuable resources of genetic
information. From among the huge collection of maize mutants, it is ultimately necessary to establish which alleles are of
the same genes and which are novel genes. Although any given mutant can be subjected to complementation tests or can be mapped
by using conventional techniques, the number of mutants at this time makes these approaches prohibitive to encompass the whole
collection. Here we describe procedures to efficiently map large numbers of mutants. Included are methods for generating polymorphic
mapping progenies, for simply and rapidly preparing samples to use in polymerase chain reaction (PCR), for tissue pooling
and application of simple sequence repeat (SSR), markers, and for stepwise determination of linkage followed by mapping to
chromosomal region. 相似文献
983.
Effects of nitrate, chloride and chlorate ions upon nitrate and chlorate uptake by roots of maize ( Zea mays L., cv. B73) seedlings were examined. Net nitrate uptake, 36 ClO3 − influx and 36 Cl− influx (the latter two in a background of 0.5 m M KNO3 ) displayed similar pH profiles with optima at pH 5.5 and below. External, non-labeled chloride had little effect on the accumulation of 36 ClO3 − (both in 5 h and 20 min uptake assays), while nitrate and chlorate had almost identical, marked inhibitory effects. Nitrate pretreatment caused an apparent induction of both 36 ClO3 − and 15 NO3 − uptake activities. After 5 h of treatment in nitrate, the uptake activities of chloride- and chlorate-pretreated plants increased to that of nitrate-pretreated plants. During 6 h exposure to chlorate, 36 ClO3 − uptake activity of nitrate-pretreated plants decreased to that of chlorate- and chloride-pretreated plants. The results support the existence of a shared nitrate/chlorate transport system in maize roots which is not inhibited by external chloride, and which is induced by nitrate, but not by chlorate or chloride. The suggestion is made that selection of chlorate-resistant mutants of maize can identify nitrate uptake as well as nitrate reductase mutants. 相似文献
984.
985.
986.
Effects of nitrogen deficiency on photosynthetic traits of maize hybrids released in different years 总被引:7,自引:0,他引:7
BACKGROUND AND AIMS: New maize (Zea mays) hybrids outperformed old ones even at reduced N rates. Understanding the mechanisms of the differences in performance between newer and older hybrids under N deficiency could provide avenues for breeding maize cultivars with large yield under N deficiency, and reduce environmental pollution caused by N fertilizers. METHODS: N deficiency effects on grain weight, plant weight, harvest index, leaf area and photosynthetic traits were studied in the field for six maize hybrids released during the past 50 years to compare their tolerance and to explore their physiological mechanisms. KEY RESULTS: N deficiency decreased grain yield and plant weight in all hybrids, especially in the older hybrids. However, there was no significant difference in harvest index, rate of light-saturated photosynthesis (Psat) 20 d before flowering, leaf area or plant weight at flowering between the N-deficient and control plants of all hybrids. Dry matter production after flowering of the N-deficient plants was significantly lower than that of the control plants in all hybrids, especially in the older hybrids, and was mostly due to differences in the rate of decrease in photosynthetic capacity during this stage. The lower Psat of the older hybrids was not due to stomatal limitation, as there was no significant difference in stomatal conductance (gs) and intercellular CO2 concentration (Ci) between the hybrids. N deficiency accelerated senescence, i.e. decreased chlorophyll and soluble protein contents, after anthesis more for the earlier released hybrids than for the later ones. N deficiency decreased phosphoenolpyruvate carboxylase (PEPCase) activity significantly more in older hybrids than newer hybrids, and affected the maximal efficiency of PSII photochemistry (Fv/Fm) only in the old hybrids and at the late stage. CONCLUSIONS: Compared with older (earlier released) hybrids, newer (later released) hybrids maintained greater plant and grain weight under N deficiency because their photosynthetic capacity decreased more slowly after anthesis, associated with smaller non-stomatal limitations due to maintenance of PEPCase activity, and chlorophyll and soluble protein content. 相似文献
987.
Denise Seitner Simon Uhse Michelle Gallei Armin Djamei 《Molecular Plant Pathology》2018,19(10):2277-2287
The biotrophic pathogen Ustilago maydis, the causative agent of corn smut disease, infects one of the most important crops worldwide – Zea mays. To successfully colonize its host, U. maydis secretes proteins, known as effectors, that suppress plant defense responses and facilitate the establishment of biotrophy. In this work, we describe the U. maydis effector protein Cce1. Cce1 is essential for virulence and is upregulated during infection. Through microscopic analysis and in vitro assays, we show that Cce1 is secreted from hyphae during filamentous growth of the fungus. Strikingly, Δcce1 mutants are blocked at early stages of infection and induce callose deposition as a plant defense response. Cce1 is highly conserved among smut fungi and the Ustilago bromivora ortholog complemented the virulence defect of the SG200Δcce1 deletion strain. These data indicate that Cce1 is a core effector with apoplastic localization that is essential for U. maydis to infect its host. 相似文献
988.
989.
990.
An integrated multi‐layered analysis of the metabolic networks of different tissues uncovers key genetic components of primary metabolism in maize 下载免费PDF全文