共查询到20条相似文献,搜索用时 31 毫秒
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Key message
Large aerial roots grow out from the branches of injured Dracaena draco trees. They integrate with the trunk or cause the branches to break off the tree and deform it.Abstract
Dracaena draco, the dragon tree, is an iconic monocot of the Canary Islands with a tree-like growth habit and some distinctive features that are unique in the plant kingdom. We report about the massive aerial roots in this tree. They appear on trees that are injured or under environmental stress and affect growth form and the whole life of the plant. We analysed the growth of these roots and tested our findings in experiments on plants. Clusters of these roots emerge from the bases of the lowest branches and growing down they may reach the soil. Descending along the trunk, they cling tightly to the trunk, integrate with it and contribute to its radial growth. This may explain (1) why the trunk of a mature D. draco tree looks fibrous, as if made of many individual strands, and (2) how some trees reach enormous radial dimensions. Alternately, a large, 2–5 m high, multi-segmented branch with aerial roots at its base, may break off the tree and grow on its own, as a mammoth off-cut, perhaps the largest known in the plant kingdom. This detachment would cause a significant reduction in the size of the crown and deform its original, highly organized pattern of branching. In the extreme condition this may result in the destruction of the mother plant. 相似文献2.
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Tracie K. Matsumoto Lisa M. Keith Roxana Y. M. Cabos Jon Y. Suzuki Dennis Gonsalves Roger Thilmony 《Plant cell reports》2013,32(3):443-451
Key message
There are multiple publications on Anthurium transformation, yet a commercial product has not been achieved. This may be due to use of non-optimum promoters here we address this problem.Abstract
Different promoters and tissue types were evaluated for transient β-glucuronidase (GUS) expression in Anthurium andraeanum Hort. ‘Marian Seefurth’ following microprojectile bombardment. Plasmids containing the Ubiquitin 2, Actin 1, Cytochrome C1 from rice, Ubiquitin 1 from maize and 35S promoter from Cauliflower Mosaic Virus fused to a GUS reporter gene were bombarded into in vitro grown anthurium lamina, somatic embryos and roots. The number of GUS foci and the intensity of GUS expression were evaluated for each construct. Ubiquitin promoters from rice and maize resulted in the highest number of expressing cells in all tissues examined. Due to the slow growth of anthurium plants, development of transgenic anthurium plants takes years. This research has rapidly identified multiple promoters that express in various anthurium tissues facilitating the development of transformation vectors for the expression of desirable traits in anthurium plants. 相似文献5.
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Albino midrib 1, encoding a putative potassium efflux antiporter,affects chloroplast development and drought tolerance in rice 总被引:2,自引:0,他引:2
Peike Sheng Junjie Tan Mingna Jin Fuqing Wu Kunneng Zhou Weiwei Ma Yueqin Heng Jiulin Wang Xiuping Guo Xin Zhang Zhijun Cheng Linglong Liu Chunming Wang Xuanming Liu Jianmin Wan 《Plant cell reports》2014,33(9):1581-1594
Key message
Mutation of the AM1 gene causes an albino midrib phenotype and enhances tolerance to drought in riceAbstract
K+ efflux antiporter (KEA) genes encode putative potassium efflux antiporters that are mainly located in plastid-containing organisms, ranging from lower green algae to higher flowering plants. However, little genetic evidence has been provided on the functions of KEA in chloroplast development. In this study, we isolated a rice mutant, albino midrib 1 (am1), with green- and white-variegation in the first few leaves, and albino midrib phenotype in older tissues. We found that AM1 encoded a putative KEA in chloroplast. AM1 was highly expressed in leaves, while lowly in roots. Chloroplast gene expression and proteins accumulation were affected during chlorophyll biosynthesis and photosynthesis in am1 mutants. Interestingly, AM1 was induced by salt and PEG, and am1 showed enhanced sensitivity to salinity in seed germination and increased tolerance to drought. Taken together, we concluded that KEAs were involved in chloroplast development and played important roles in drought tolerance. 相似文献8.
Lili Wang Changchun Yu Cong Chen Chunlan He Yingguo Zhu Wenchao Huang 《Plant cell reports》2014,33(12):2047-2062
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Antoaneta B. M. Kroumova Dipak K. Sahoo Sumita Raha Michael Goodin Indu B. Maiti George J. Wagner 《Plant cell reports》2013,32(11):1771-1782
Key message
Phylloplanins are plant-derived, antifungal glycoproteins produced by leaf trichomes. Expression of phylloplanin-GFP fusion gene to the apoplast of a blue mold susceptible tobacco resulted in increased resistance to this pathogen.Abstract
Tobaccos and certain other plants secrete phylloplanin glycoproteins to aerial surfaces where they appear to provide first-point-of-contact resistance against fungi/fungi-like pathogens. These proteins can be collected by water washing of aerial plant surfaces, and as shown for tobacco and a sunflower phylloplanins, spraying concentrated washes onto, e.g., turf grass aerial surfaces can provide resistance against various fungi/fungi-like pathogens, in the laboratory. These results suggest that natural-product, phylloplanins may be useful as broad-selectivity fungicides. An obvious question now is can a tobacco phylloplanin gene be introduced into a disease-susceptible plant to confer endogenous resistance. Here we demonstrate that introduction of a tobacco phylloplanin gene—as a fusion with the GFP gene—targeted to the apoplasm can increase resistance to blue mold disease in a susceptible host tobacco. 相似文献12.
Patrik Mészáros Ľubomír Rybanský Nadine Spieß Peter Socha Roman Kuna Jana Libantová Jana Moravčíková Beáta Piršelová Pavol Hauptvogel Ildikó Matušíková 《Plant cell reports》2014,33(11):1789-1799
Key message
Chitinases in Glycine max roots specifically respond to different metal types and reveal a polymorphism that coincides with sensitivity to metal toxicity.Abstract
Plants evolved various defense mechanisms to cope with metal toxicity. Chitinases (EC 3.2.1.14), belonging to so-called pathogenesis-related proteins, act as possible second line defense compounds in plants exposed to metals. In this work their activity was studied and compared in two selected soybean (Glycine max L.) cultivars, the metal-tolerant cv. Chernyatka and the sensitive cv. Kyivska 98. Roots were exposed to different metal(loid)s such as cadmium, arsenic and aluminum that are expected to cause toxicity in different ways. For comparison, a non-metal, NaCl, was applied as well. The results showed that the sensitivity of roots to different stressors coincides with the responsiveness of chitinases in total protein extracts. Moreover, detailed analyses of acidic and neutral proteins identified one polymorphic chitinase isoform that distinguishes between the two cultivars studied. This isoform was stress responsive and thus could reflect the evolutionary adaptation of soybean to environmental cues. Activities of the individual chitinases were dependent on metal type as well as the cultivar pointing to their more complex role in plant defense during this type of stress. 相似文献13.
Wan-Ze Zhu San-Gen Wang De-Zhen Yu Yong Jiang Mai-He Li 《Trees - Structure and Function》2014,28(2):359-372
Key message
Above- and belowground tissues showed different trends in IAA, CTK and CTK/IAA ratios with elevations, and coppicing changed the levels of endogenous hormones that are related to resprouting ability.Abstract
Little is known about how plant hormones and nitrate concentrations change in plants with increasing elevations, and whether the alpine treeline formation and the decreased resprouting ability of plants at high elevations are correlated with such changes. We studied tissue hormones and nitrate concentrations in Quercus aquifolioides plants before and after coppicing at 3,000, 3,500 m, and their uppermost distribution of 3,950 m a.s.l. in southwestern China. Concentrations of indole-3-acetic acid (IAA) significantly increased, but concentrations of cytokinins (CTK) and CTK/IAA ratios decreased in aboveground tissues of intact plants with increasing elevations. The altitude had reverse effects on these parameters in belowground tissue. Coppicing changed the levels of IAA, CTK, and nitrate concentrations, as well as the CTK/IAA ratios, but not their elevational patterns in either stumps or roots. These results imply that the elevational patterns of plant hormones reflect mainly the effects of altitude associated with gradual changes in temperature and radiation condition on hormones along an elevational gradient. Both CTK concentrations and CTK/IAA ratios in stumps were significantly positively correlated with resprouting ability, but in fine roots they were negatively correlated. This indicates that CTK, which is synthesized in the root cap, needs to move from the roots into the stumps to initiate the growth of lateral buds. Our results suggest that for coppice regeneration management practices to be successful, the root system needs to be carefully protected from damage. 相似文献14.
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The Arabidopsis SAUR36 , renamed RAG1 , integrates auxin and gibberellin signals to regulate apical hook maintenance in etiolated seedlings, hypocotyl elongation in the light and fertility.Abstract
Phytohormone signalling intermediates integrate responses to developmental cues and the variety of environmental inputs thereby governing all aspects of plant growth and development. At the genetic level, interactions of different phytohormone signalling pathways lead to the regulation of overlapping sets of target genes. We have characterised SMALL AUXIN UP RNA 36 (SAUR36, At2g45210) whose expression is induced by auxins and repressed by gibberellins. Its expression appears to be restricted to elongating tissues. Germination responses to treatments with paclobutrazol and exogenous abscisic acid were affected in knock-out, knock-down as well as ectopic expression lines. At later stages of development, however, transgenic plants with reduced levels of SAUR36 expression appeared similar to wild-type plants, while ectopic expression of SAUR36 led to the absence of apical hooks in etiolated seedlings and longer hypocotyls in light-grown seedlings. Mature plants ectopically expressing SAUR36 further displayed strongly reduced fertility and wavy growth of inflorescence axes, the latter of which could be linked to defects in auxin transport. Taken together, our data suggest that SAUR36 plays a role in the regulation of seed germination by gibberellins and abscisic acid, light-dependent hypocotyl elongation as well as apical hook formation or maintenance. Therefore, we propose that it could act as one of the converging points of auxin and gibberellin signal integration in controlling key plant developmental events. Hence, we named the gene RESPONSE TO AUXINS AND GIBBERELLINS 1 (RAG1). 相似文献17.
Yiru Chen Yordan S. Yordanov Cathleen Ma Steven Strauss Victor B. Busov 《Plant cell reports》2013,32(3):453-463
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Auxin responsive promoter DR5 reporter system is functional in Populus to monitor auxin response in tissues including leaves, roots, and stems.Abstract
We described the behavior of the DR5::GUS reporter system in stably transformed Populus plants. We found several similarities with Arabidopsis, including sensitivity to native and synthetic auxins, rapid induction after treatment in a variety of tissues, and maximal responses in root tissues. There were also several important differences from Arabidopsis, including slower time to maximum response and lower induction amplitude. Young leaves and stem sections below the apex showed much higher DR5 activity than did older leaves and stems undergoing secondary growth. DR5 activity was highest in cortex, suggesting high levels of auxin concentration and/or sensitivity in this tissue. Our study shows that the DR5 reporter system is a sensitive and facile system for monitoring auxin responses and distribution at cellular resolution in poplar. 相似文献18.
Guo-qing Song Aaron Walworth Dongyan Zhao Ning Jiang James F. Hancock 《Plant cell reports》2013,32(11):1759-1769
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The blueberry FLOWERING LOCUS T ( FT )-like gene ( VcFT ) cloned from the cDNA of a tetraploid, northern highbush blueberry ( Vaccinium corymbosum L.) is able to reverse the photoperiodic and chilling requirements and drive early and continuous flowering.Abstract
Blueberry is a woody perennial bush with a longer juvenile period than annual crops, requiring vernalization to flower normally. Few studies have been reported on the molecular mechanism of flowering in blueberry or other woody plants. Because FLOWERING LOCUS T (FT) from Arabidopsis thaliana plays a multifaceted role in generating mobile molecular signals to regulate plant flowering time, isolation and functional analysis of the blueberry (Vaccinium corymbosum L.) FT-like gene (VcFT) will facilitate the elucidation of molecular mechanisms of flowering in woody plants. Based on EST sequences, a 525-bpVcFT was identified and cloned from the cDNA of a tetraploid, northern highbush blueberry cultivar, Bluecrop. Ectopic expression of 35S:VcFT in tobacco induced flowering an average of 28 days earlier than wild-type plants. Expression of the 35S:VcFT in the blueberry cultivar Aurora resulted in an extremely early flowering phenotype, which flowered not only during in vitro culture, a growth stage when nontransgenic shoots had not yet flowered, but also in 6–10-week old, soil-grown transgenic plants, in contrast to the fact that at least 1 year and 800 chilling hours are required for the appearance of the first flower of both nontransgenic ‘Aurora’ and transgenic controls with the gusA. These results demonstrate that the VcFT is a functional floral activator and overexpression of the VcFT is able to reverse the photoperiodic and chilling requirements and drive early and continuous flowering. 相似文献19.
Nader Ahmed Darwish Raham Sher Khan Valentine Otang Ntui Ikuo Nakamura Masahiro Mii 《Plant cell reports》2014,33(3):411-421