Australian Journal of Plant Physiology最新文献

{"title":"Different leaf surface characteristics of three grape cultivars affect leaf optical properties as measured with fibre optics: possible implication in stress tolerance","authors":"G. Karabourniotis, J. Bornman, V. Liakoura","doi":"10.1071/PP98052","DOIUrl":"https://doi.org/10.1071/PP98052","url":null,"abstract":"Young leaves of three grape cultivars having different surface characteristics (cv. Athiri, pubescent; cv. Soultanina, glabrous green; and cv. Fraoula, glabrous red-brown) only during the early stages of their development, were used to investigate the potential, differential effect of a trichome layer or a pigmented epidermis on the light microenvironment within the mesophyll. The penetration of forward propagated 310, 360 and 430 nm radiation into the leaf tissues was monitored using a quartz fibre-optic microprobe. The mesophyll of the young leaves of Athiri was much better protected from ultraviolet-A, ultraviolet-B and high visible radiation compared to the other two cultivars. Abaxial, as well as adaxial trichome layers attenuated almost all incident radiation at 310 nm and 360 nm and a considerable part of the blue light (430 nm). No significant differences in light attenuation from epidermal and mesophyll layers between the other two cultivars were observed. The adaxial epidermis of young and dehaired leaves of cv. Athiri was largely ineffective in absorbing the incident ultraviolet- B radiation. In addition, the dehaired lamina of such leaves exhibited 80% lower relative concentration of ultraviolet-absorbing compounds per leaf surface area, compared to leaves of similar ontogenetic stage in the cv. Soultanina. It is proposed that the occurrence of a dense trichome layer in young leaves, besides other proposed functions, may play a protective role against not only ultraviolet radiation damage, but also against high insolation. This protection could be advantageous under stress conditions during leaf development.","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"59 5 1","pages":"47-53"},"PeriodicalIF":0.0,"publicationDate":"2018-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87726314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plant water use efficiency of 17 Australian NAD-ME and NADP-ME C₄ grasses at ambient and elevated CO₂ partial pressure","authors":"O. Ghannoum, S. Caemmerer, J. Conroy","doi":"10.1071/PP01056","DOIUrl":"https://doi.org/10.1071/PP01056","url":null,"abstract":"This study investigates the response to elevated CO2 partial pressure (pCO2) of C4grasses belonging to different biochemical subtypes (NAD–ME and NADP–ME), and taxonomic groups (main Chloroid assemblage, Paniceae and Andropogoneae). Seventeen C4 grasses were grown under well-watered conditions in two glasshouses maintained at an average dailyppCO2 of 42 (ambient) or 68 (elevated) Pa. Elevated pCO2 significantly increased plant water-use efficiency (WUE; dry matter gain per unit water transpired) in 12 out of the 17 C4 grasses, by an average of 33%. In contrast, only five species showed a significant growth stimulation. When all species are considered, the average plant dry mass enhancement at elevated pCO2 was 26%. There were no significant subtype (or taxa) × pCO2 interactions on either WUE or biomass accumulation. When leaf gas exchange was compared at growth pCO2 but similar light and temperature, high pCO2-grown plants had similar CO2 assimilation rates (A) but a 40% lower stomatal conductance than their low pCO2-grown counterparts. There were no signs of either photosynthetic or stomatal acclimation in any of the measured species. We conclude that elevated pCO2 improved WUE primarily by reducing stomatal conductance.","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"2 1","pages":"1207-1217"},"PeriodicalIF":0.0,"publicationDate":"2001-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82165071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Localisation and expression of zeaxanthin epoxidase mRNA in Arabidopsis in response to drought stress and during seed development","authors":"C. Audran, S. Liotenberg, M. Gonneau, Helen M. North, A. Frey, Karine Tap-Waksman, N. Vartanian, A. Marion-Poll","doi":"10.1071/PP00134","DOIUrl":"https://doi.org/10.1071/PP00134","url":null,"abstract":"Abscisic acid (ABA) is involved in seed development and plant adaptation to environmental stresses. ABA is synthesized from cleaved xanthophylls and zeaxanthin epoxidase (ZEP) is the enzyme responsible for the conversion of zeaxanthin to violaxanthin. In this study, we have characterized the ABA1 gene (AtZEP) of Arabidopsis thaliana L. and show that this complements the aba1 mutant, defective in zeaxanthin epoxidation. The molecular basis for two aba1 mutant alleles has been determined and the reduction in their AtZEP transcript levels correlates with the molecular defect identified. As AtZEP mRNA abundance was not affected in two other ABA-deficient mutants (aba2 and aba3) and in two ABA-insensitive mutants (abi1 and abi2), no feedback regulation of ABA biosynthesis seems to occur at the level of ZEP transcription. Steady state transcript levels increased in roots during rapid water stress as well as progressive drought stress, providing evidence that zeaxanthin epoxidation contributed to the regulation of ABA biosynthesis in roots and consequently to the plant adaptive response to hydric stress. In seeds in situ hybridization analysis detected AtZEP mRNA in the embryo cells from the globular stage to desiccation phase. In contrast, expression of AtZEP in maternal tissues was specific to the maturation phase. These results are discussed in relation to the role of ABA both in response to drought stress and in seed development.","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"6 1","pages":"1161-1173"},"PeriodicalIF":0.0,"publicationDate":"2001-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84605743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of manipulation of pyruvate decarboxylase and alcohol dehydrogenase levels on the submergence tolerance of rice","authors":"Musrur Rahman, A. Grover, W. Peacock, E. Dennis, M. Ellis","doi":"10.1071/PP00137","DOIUrl":"https://doi.org/10.1071/PP00137","url":null,"abstract":"A transgenic approach was taken to manipulate the levels of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) in rice, in order to investigate whether alteration of ethanol fermentation can affect anaerobic tolerance. A line transformed with an antisense Adh1 construct had only 4–8% of the ADH activity of untransformed plants. This line showed reduced ethanol production and coleoptile growth under anoxia. Mature plants had reduced survival when submerged in water and exposed to anoxia, suggesting that ADH plays an essential role in seed germination and plant survival in the absence of O2. A transgenic line transformed with a cotton Adh2 cDNA in the sense orientation relative to a constitutive promoter, showed 3–4-fold more ADH activity than either untransformed controls, or a flooding-tolerant rice variety (FR13A), both in air and under hypoxia. However, ethanol production by this line was only slightly higher than that of untransformed controls, and there was no increase in survival following anoxia treatments. Three independent transgenic lines containing the ricePdc1 cDNA driven by an anaerobically-inducible promoter (6XARE) showed an increase in PDC1 polypeptide in shoots, but not in roots or endosperm. A moderate increase in PDC activity and ethanol production was observed in shoots of these lines under anaerobic conditions, as well as decreased survival of shoots when submerged and exposed to anoxia. F1 plants containing both the PDC and ADH constructs showed levels of anoxia-tolerance similar to those of untransformed plants. These results suggest that over-production of PDC may be toxic to rice plants because of increased acetaldehyde. Consistent with this view, acetaldehyde levels were appreciably higher in plants over-producing PDC, compared with untransformed plants, or hybrid lines containing both the PDC and ADH constructs.","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"19 1","pages":"1231-1241"},"PeriodicalIF":0.0,"publicationDate":"2001-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81856338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cold-induced photoinhibition and foliar pigment dynamics of Eucalyptus nitens seedlings during establishment","authors":"D. Close, C. Beadle, M. Hovenden","doi":"10.1071/PP01039","DOIUrl":"https://doi.org/10.1071/PP01039","url":null,"abstract":"The effects of cold-induced photoinhibition on chlorophyll and carotenoid dynamics and xanthophyll cycling in Eucalyptus nitens (Deane and Maiden) Maiden were assessed between planting and 32 weeks after planting. The seedlings were fertilised or nutrient-deprived (non-fertilised) before planting and shaded or not shaded after planting. The experimental site was 700 m a.s.l., which is considered marginal for establishment of E. nitens plantations in Tasmania due to low mean annual minimum temperatures. Low temperature–high light conditions caused a reduction in variable to maximal chlorophyll fluorescence ratio (F v /F m ), which was more pronounced in non-fertilised than in fertilised seedlings. Shadecloth shelters alleviated this depression. Except in shaded fertilised seedlings, F v /F m did not recover to the level before planting until after 20 weeks. Total chlorophyll content was initially reduced in shaded treatments but subsequently increased with increasing temperatures and F v /F m. Total xanthophyll content and xanthophylls per unit chlorophyll remained relatively constant in fertilised seedlings but decreased in non-fertilised seedlings within 2 weeks after planting. Total xanthophyll and xanthophylls per unit chlorophyll subsequently recovered in non-shaded, non-fertilised seedlings with increasing temperatures and F v /F m. Diurnal [yield and non-photochemical quenching (NPQ) and seasonal (F v /F m) variation in chlorophyll fluorescence parameters were not reflected in xanthophyll cycling during the period of most severe photoinhibition. This result may indicate that chlorophyll–xanthophylls protein complexes form in winter-acclimated E. nitens foliage as have been demonstrated to occur in Eucalyptus pauciflora Sieb. ex Spreng. (Gilmore and Ball 2000, Proceedings of the National Academy of Sciences USA 97, 11098–11101).","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"1 1","pages":"1133-1141"},"PeriodicalIF":0.0,"publicationDate":"2001-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90108905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and expression of a cinnamyl alcohol dehydrogenase cDNA from perennial ryegrass (Lolium perenne)","authors":"Fiona M. McAlister, W. R. Lewis-Henderson, Colin L. D. Jenkins, J. Watson","doi":"10.1071/PP00046","DOIUrl":"https://doi.org/10.1071/PP00046","url":null,"abstract":"A perennial ryegrass (Lolium perenne L.) cDNA library was screened with a PCR-amplified cad DNA fragment generated from ryegrass cDNA template using degenerate oligonucleotide primers. A full-length cDNA (LpeCad1) was isolated and confirmed to encode a cinnamyl alcohol dehydrogenase (CAD) enzyme by expression of activity in Escherichia coli. The recombinant enzyme catalyses conversion of coniferaldehyde and sinapaldehyde with similar efficiency, and apparent K m values below 10 µM were determined for these substrates, whereas weak substrate inhibition occurs above this concentration. The predicted perennial ryegrass CAD was very similar (88–87percnt; amino acid sequence identity) to the only other monocotyledonous plant CAD sequences available, those of maize and sugarcane, respectively. Southern blot hybridization analysis indicated that there may be two or three cad genes, or alleles, in perennial ryegrass. The ryegrass LpeCad1 gene resembles the maize cadgene in showing strong expression in root and stem tissues, but is also expressed at lower levels in shoot, leaf sheath, leaf blade and floral tissues.","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"53 1","pages":"1085-1094"},"PeriodicalIF":0.0,"publicationDate":"2001-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77119927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of leaf age on internal CO2 transfer conductance and photosynthesis in tree species having different types of shoot phenology","authors":"Y. Hanba, Shin-Ichi Miyazawa, H. Kogami, I. Terashima","doi":"10.1071/PP00102","DOIUrl":"https://doi.org/10.1071/PP00102","url":null,"abstract":"We examined the changes in leaf anatomy and some physiological characteristics during leaf expansion and maturation. Three deciduous tree species having different types of shoot phenology, maple (Acer mono Maxim.; ‘flush’ type), alder (Alnus japonica(Thunb.) Steud.; ‘successive’ type), and Japanese poplar (Populus maximowiczii A. Henry; ‘successive’ type), were studied. Leaf CO 2 assimilation rate at high irradiance (P max) and CO 2 transfer conductance inside the leaf (g i) varied significantly with leaf development. There were strong positive relationships between P max) and g i for all of the species. The variations in g i were partly related to those in the surface area of chloroplasts facing the intercellular airspaces, while some other factors that related to liquid phase conductance may also contribute to the variation in g i . The developments of mesophyll cells were accompanied by the concomitant increase in chloroplast and Rubisco content in Alnus and Populus (successive types).","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"37 1","pages":"1075-1084"},"PeriodicalIF":0.0,"publicationDate":"2001-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84185037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural abundance of stable carbon and nitrogen isotopes in Cannabis sativa reflects growth conditions","authors":"Tricia M. Denton, S. Schmidt, C. Critchley, G. Stewart","doi":"10.1071/PP01066","DOIUrl":"https://doi.org/10.1071/PP01066","url":null,"abstract":"Stable carbon and nitrogen isotope signatures (delta C-13 and delta N-15) of Cannabis sativa were assessed for their usefulness to trace seized Cannabis leaves to the country of origin and to source crops by determining how isotope signatures relate to plant growth conditions. The isotopic composition of Cannabis examined here covered nearly the entire range of values reported for terrestrial C-3 plants. The delta C-13 values of Cannabis from Australia, Papua New Guinea and Thailand ranged from -36 to -25 parts per thousand, and delta N-15 values ranged from -1.0 to 15.8 parts per thousand. The stable isotope content did not allow differentiation between Cannabis originating from the three countries, but delta C-13 values of plantation-grown Cannabis differed between well-watered plants (average delta C-13 of -30.0 parts per thousand) and plants that had received little irrigation (average delta C-13 of -26.4 parts per thousand). Cannabis grown under controlled conditions had delta C-13 values of -32.6 and -30.6 parts per thousand with high and low water supply, respectively. These results indicate that water availability determines leaf C-13 in plants grown under similar conditions of light, temperature and air humidity. The delta C-13 values also distinguished between indoor- and outdoor-grown Cannabis; indoor- grown plants had overall more negative delta C-13 values (average -31.8 parts per thousand) than outdoor-grown plants (average -27.9 parts per thousand). Contributing to the strong C-13-depletion of indoor- grown plants may be high relative humidity, poor ventilation and recycling of C-13-depleted respired CO2. Mineral fertilizers had mostly lower delta N-15 values (-0.2 to 2.2 parts per thousand) than manure-based fertilizers (7.6 to 22.7 parts per thousand). It was possible to link delta N-15 values of fertilizers associated with a crop site to soil and plant delta N-15 values. The strong relationship between soil, fertilizer, and plant delta N-15 suggests that Cannabis delta N-15 is determined by the isotopic composition of the nitrogen source. The distinct delta N-15 values measured in Cannabis crops make delta N-15 an excellent tool for matching seized Cannabis with a source crop. A case study is presented that demonstrates how delta C-13 and delta N-15 values can be used as a forensic tool.","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"10 1","pages":"1005-1012"},"PeriodicalIF":0.0,"publicationDate":"2001-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87551165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A simplified model for assessing critical parameters during associative 15N2 fixation between Azospirillum and wheat","authors":"C. Wood, N. Islam, R. Ritchie, I. Kennedy","doi":"10.1071/PP01036","DOIUrl":"https://doi.org/10.1071/PP01036","url":null,"abstract":"Detailed studies in field experiments have shown repeatedly that the transfer of 15 N 2 fixed by diazotrophic bacteria to wheat tissue is minimal. Here, a simple and convenient laboratory co-culture model was designed to assess important features of the association between Azospirillum brasilense and wheat, such as the rate of nitrogen fixation (acetylene reduction), ammonia excretion from the bacterium and the transfer of newly fixed 15 N 2 from the associative diazotroph to the shoot tissue of wheat plants. After 70 h, in this model, insignificant amounts of newly fixed N 2 were transferred from an ammonia-excreting strain of A. brasilense to the shoot tissue of wheat. However, when malate was added to the co-culture the 15 N enrichment of the shoot tissue increased 48-fold, indicating that 20% of shoot N had been derived from N 2 fixation. Thus, the inability of the host plant to release carbon in the rhizosphere is a significant constraint in the development of associative N 2 -fixing systems. These specific results suggest that wheat plants with an increased release ofphotosynthate to the rhizosphere should be a priority for the future development of broad-acre agricultural systems that are more self-sufficient for nitrogen nutrition. The simplicity of the model for assessing the critical parameters of associative 15 N 2 fixation may allow large-scale surveys of plant-bacterial interactions to be conducted and a selection of improved associations for further study.","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"209 1","pages":"969-974"},"PeriodicalIF":0.0,"publicationDate":"2001-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72653991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biological nitrogen fixation associated with tropical pasture grasses","authors":"V. Reis, Fábio Bueno dos Reis, D. Quesada, O. C. Oliveira, B. Alves, S. Urquiaga, R. Boddey","doi":"10.1071/PP01079","DOIUrl":"https://doi.org/10.1071/PP01079","url":null,"abstract":"The semi-humid or humid tropics are ideal for the production of large quantities of biomass from fast-growing C 4 grasses, but high yields normally require large quantities of fertiliser, especially N, which has a very high input from fossil fuels (natural gas). A program has been started recently to use elephant grass (Pennisetum purpureum Schum.) to substitute firewood as a fuel and also to make charcoal for iron production. In this case, any large N fertiliser additions would mean that the yield of bio fuel per unit of fossil fuel invested would be detrimentally affected. In this study, we report on the potential for the selection of genotypes of fast-growing C 4 tropical grasses ofthe genera Pennisetum and Brachiaria for their capacity to obtain N inputs from plant-associated biological nitrogen fixation (BNF). Fourteen genotypes each of Brachiaria and Pennisetum were screened for BNF contributions by growing them in 15 N-labelled soil. In the case of the Pennisetum, after a suitable cutting height for the crop had been selected, there were large differences in dry matter production, N accumulation and 15 N enrichment. The differences in 15 N enrichment between genotypes were statistically significant and BNF inputs were estimated as high as 41% of accumulated N. In the study on Brachiaria genotypes, potential inputs of BNF seemed lower. Only one or two genotypes of B. brizantha and B. ruziziensis obtained more then 20% of their N from BNF. The N 2 -fixing bacteria that were most commonly associated with shoots and roots the Pennisetum genotypes were of the genus Herbaspirillum, but predominantly of a recently described new species. The Brachiaria spp. from three different sites (Rio de Janeiro, Goania, Bahia) were predominately colonised by Azospirillum spp., most of the isolates being of the species Azospirillum amazonense. Very few Herbaspirilla were isolated from these plants.","PeriodicalId":8650,"journal":{"name":"Australian Journal of Plant Physiology","volume":"54 1","pages":"837-844"},"PeriodicalIF":0.0,"publicationDate":"2001-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75898291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}