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1.
StGA2ox1 is induced prior to stolon swelling and controls GA levels during potato tuber development 总被引:3,自引:0,他引:3
Kloosterman B Navarro C Bijsterbosch G Lange T Prat S Visser RG Bachem CW 《The Plant journal : for cell and molecular biology》2007,52(2):362-373
The formation and growth of a potato ( Solanum tuberosum ) tuber is a complex process regulated by different environmental signals and plant hormones. In particular, the action of gibberellins (GAs) has been implicated in different aspects of potato tuber formation. Here we report on the isolation and functional analysis of a potato GA 2-oxidase gene ( StGA2ox1 ) and its role in tuber formation. StGA2ox1 is upregulated during the early stages of potato tuber development prior to visible swelling and is predominantly expressed in the subapical region of the stolon and growing tuber. 35S-over-expression transformants exhibit a dwarf phenotype, reduced stolon growth and earlier in vitro tuberization. Transgenic plants with reduced expression levels of StGA2ox1 showed normal plant growth, an altered stolon swelling phenotype and delayed in vitro tuberization. Tubers of the StGA2ox1 suppression clones contain increased levels of GA20 , indicating altered GA metabolism. We propose a role for StGA2ox1 in early tuber initiation by modifying GA levels in the subapical stolon region at the onset of tuberization, thereby facilitating normal tuber development and growth. 相似文献
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Efstathios Roumeliotis Bjorn Kloosterman Marian Oortwijn Theo Lange Richard G.F. Visser Christian W.B. Bachem 《Journal of plant physiology》2013
GA biosynthesis and catabolism has been shown to play an important role in regulating tuberization in potato. Active GAs are inactivated in the stolon tips shortly after induction to tuberization. Overexpression of a GA inactivation gene results in an earlier tuberization phenotype, while reducing expression of the same gene results in delayed tuberization. In addition, overexpression of genes involved in GA biosynthesis results in delayed tuberization, while decreased expression of those genes results in earlied tuberization. The final step in GA biosynthesis is catalysed by StGA3ox1 and StGA3ox2 activity, that convert inactive forms of GA into active GA1 and GA4. In this study we cloned StGA3ox2 gene in an RNAi construct and used this construct to transform potato plants. The StGA3ox2 silenced plants were smaller and had shorter internodes. In addition, we assayed the concentrations of various GAs in the transgenic plants and showed an altered GA content. No difference was observed on the time point of tuber initiation. However, the transgenic clones had increased number of tubers with the same yield, resulting in smaller average tuber weight. In addition, we cloned the promoter of StGA3ox2 to direct expression of the GUS reporter gene to visualize the sites of GA biosynthesis in the potato plant. Finally, we discuss how changes of several GA levels can have an impact on shoot, stolon and tuber development, as well as the possible mechanisms that mediate feed-forward and feed-back regulation loops in the GA biosynthetic pathway in potato. 相似文献
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Ivan Šimko 《Journal of Plant Growth Regulation》1994,13(2):73-77
Stems of potato plants (Solanum tuberosum L. cv. Dianella) were immersed in solutions containing water (control), sucrose, glucose, paclobutrazol, and gibberellic acid. The effects of these treatments on the ethylene release, levels of endogenous gibberellins, glucose, sucrose, and starch were correlated with tuberization of nodal cuttings, excised from potato stems. Paclobutrazol and sucrose improved the percent of tuberization and/or increased tuber weight. In contrast, GA3 inhibited tuber formation compared with the control. The level of endogenous free GAs was negatively correlated with percent tuberization. However, the level of conjugated GAs was positively correlated with both percent tuberization and tuber weight. The effect of sucrose on potato tuber induction in relation to the possible role of sucrose in GA-conjugate formation is discussed. 相似文献
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Overexpression of jasmonic acid carboxyl methyltransferase increases tuber yield and size in transgenic potato 总被引:3,自引:0,他引:3
Hwang Bae Sohn Han Yong Lee Ju Seok Seo Choonkyun Jung Jae Heung Jeon Jeong-Han Kim Yin Won Lee Jong Seob Lee Jong-Joo Cheong Yang Do Choi 《Plant biotechnology reports》2011,5(1):27-34
Jasmonates control diverse plant developmental processes, such as seed germination, flower, fruit and seed development, senescence
and tuberization in potato. To understand the role of methyl jasmonate (MeJA) in potato tuberization, the Arabidopsis
JMT gene encoding jasmonic acid carboxyl methyltransferase was constitutively overexpressed in transgenic potato plants. Increases
in tuber yield and size as well as in vitro tuberization frequency were observed in transgenic plants. These were correlated
with JMT mRNA level––the higher expression level, the higher the tuber yield and size. The levels of jasmonic acid (JA), MeJA and
tuberonic acid (TA) were also higher than those in control plants. Transgenic plants also exhibited higher expression of jasmonate-responsive
genes such as those for allene oxide cyclase (AOC) and proteinase inhibitor II (PINII). These results indicate that JMT overexpression induces jasmonate biosynthesis genes and thus JA and TA pools in transgenic potatoes. This results in enhanced
tuber yield and size in transgenic potato plants. 相似文献
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Stephen D. Jackson Arnd Heyer Jessyca Dietze Salomé Prat 《The Plant journal : for cell and molecular biology》1996,9(2):159-166
To determine whether phytochrome B is involved in the response of potato plants to photoperiod, a potato PHYB cDNA fragment was inserted in the antisense orientation behind the 35S CaMV promoter in Bin19 and this construct was transformed into Solanum tuberosum ssp. andigena plants which normally require short days for tuberization. Two independent transformants were obtained that had much lower levels of PHYB mRNA and protein, and which exhibited phenotypes characteristic of phyB mutants, for example, elongated stems and decreased chlorophyll content. The level of phyA, and of several phytochrome A-controlled responses, was unaffected in these plants. The photoperiodic control of tuberization in these antisense PHYB plants was abolished, the plants tuberizing in short day, long day, or short day plus night break conditions. This result shows that phytochrome B is required for the photoperiodic control of tuberization in potato ( Solanum tuberosum ssp. andigena ) and that it regulates this developmental process by preventing tuber formation in non-inductive photoperiods rather than by promoting tuberization in inductive photoperiods. 相似文献
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Gibberellin A1 metabolism contributes to the control of photoperiod-mediated tuberization in potato 总被引:1,自引:0,他引:1
Some potato species require a short-day (SD) photoperiod for tuberization, a process that is negatively affected by gibberellins (GAs). Here we report the isolation of StGA3ox2, a gene encoding a GA 3-oxidase, whose expression is increased in the aerial parts and is repressed in the stolons after transfer of photoperiod-dependent potato plants to SD conditions. Over-expression of StGA3ox2 under control of constitutive or leaf-specific promoters results in taller plants which, in contrast to StGA20ox1 over-expressers previously reported, tuberize earlier under SD conditions than the controls. By contrast, StGA3ox2 tuber-specific over-expression results in non-elongated plants with slightly delayed tuber induction. Together, our experiments support that StGA3ox2 expression and gibberellin metabolism significantly contribute to the tuberization time in strictly photoperiod-dependent potato plants. 相似文献
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Mi Sun Kim Hyun Soon Kim Han Na Kim Yoon Shik Kim Kwang Hyun Baek Youn Il Park Hyouk Joung Jae Heung Jeon 《Journal of Plant Biology》2007,50(4):490-495
Overexpression of a chloroplast-localized Cu/Zn superoxide dismutase (chCu/ZnSOD) obtained from lily significantly affects
the growth and shape of potato tubers from anin vitro culture system (Kim et al., 2007). Here, we further characterized the sense and antisense transgenic potatoes grown and pots
and the greenhouse to investigate the potential for more practical field applications of such phenotypic manipulations. Underin vitro conditions, antisense transgenic plants showed increased shoot growth, delayed tuberization, and altered tuber shapes. When
antisense plants were treated with paclobutrazol, an inhibitor of GA biosynthesis, tuberization efficiency and tuber shape
were recovered to a status very similar to that ofin vitro- grown wild-type plants. Our results strongly support the idea that potato tuberization and shape is mediated by SOD-catalyzed
reactive oxygen species, possibly via the GA biosynthesis pathway. 相似文献
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The Role of Gibberellin, Abscisic Acid, and Sucrose in the
Regulation of Potato Tuber Formation in Vitro 总被引:21,自引:1,他引:20 下载免费PDF全文
The effects of plant hormones and sucrose (Suc) on potato (Solanum tuberosum L.) tuberization were studied using in vitro cultured single-node cuttings. Tuber-inducing (high Suc) and -noninducing (low Suc or high Suc plus gibberellin [GA]) media were tested. Tuberization frequencies, tuber widths, and stolon lengths were measured during successive stages of development. Endogenous GAs and abscisic acid (ABA) were identified and quantified by high-performance liquid chromatography and gas chromatography-mass spectrometry. Exogenous GA4/7 promoted stolon elongation and inhibited tuber formation, whereas exogenous ABA stimulated tuberization and reduced stolon length. Indoleacetic acid-containing media severely inhibited elongation of stolons and smaller sessile tubers were formed. Exogenous cytokinins did not affect stolon elongation and tuber formation. Endogenous GA1 level was high during stolon elongation and decreased when stolon tips started to swell under inducing conditions, whereas it remained high under noninducing conditions. GA1 levels were negatively correlated with Suc concentration in the medium. We conclude that GA1 is likely to be the active GA during tuber formation. Endogenous ABA levels decreased during stolon and tuber development, and ABA levels were similar under inducing and noninducing conditions. Our results indicate that GA is a dominant regulator in tuber formation: ABA stimulates tuberization by counteracting GA, and Suc regulates tuber formation by influencing GA levels. 相似文献
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Changes in GA 20-oxidase gene expression strongly affect stem length, tuber induction and tuber yield of potato plants 总被引:18,自引:0,他引:18
Carrera E Bou J García-Martínez JL Prat S 《The Plant journal : for cell and molecular biology》2000,22(3):247-256
Gene StGA20ox1 encoding potato GA 20-oxidase is expressed to relatively high levels in leaves and regulated by daylength. To investigate whether this gene is involved in photoperiodic regulation of tuber formation, we have obtained transgenic potato plants expressing sense and antisense copies of the StGA20ox1 cDNA. Over-expression of this cDNA resulted in taller plants that required a longer duration of a short day photoperiod (SD) to tuberize. Tubers from these plants had a decreased time of dormancy and developed sprouts with elongated internodes. Plants expressing antisense copies of the StGA20ox1 cDNA had shorter stems, a decreased length of the internodes and tuberized earlier than control plants, showing increased tuber yields. Antisense inhibition of this gene had no visible effect on the time of dormancy of the tubers, although at the end of dormancy these formed sprouts with shortened internodes. Decreased levels of endogenous GA20 and GA1 were detected in the apex and first leaves of the antisense lines. These results demonstrate the involvement of the GA 20-oxidase activity encoded by StGA20ox1 in the control of stem elongation and in tuber induction but not in tuber dormancy, indicating that the latter may be regulated by another member of the gene family. 相似文献
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M Raíces G C MacIntosh R M Ulloa P R Gargantini N F Vozza M T Téllez-Inón 《Cellular and molecular biology, including cyto-enzymology》2003,49(6):959-964
The effect of sucrose on tuber formation, calcium-dependent protein kinase (CDPK) and phosphatase activities was analysed using in vitro cultured potato plants. In short treatments, sucrose induced CDPK and phosphatase activities. In long treatments, sucrose induced tuber formation in the absence of other tuber inducing stimuli. Sorbitol caused a minor increase in CDPK activity and affected plant morphology but did not induce tuber development. The addition of the protein kinase inhibitor Staurosporine precluded sucrose-induced tuberization. Altogether, our results suggest that phosphorylation/dephosphorylation events are involved in sucrose-induced tuber development. 相似文献
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Som Dutt Anshul Sharma Manjul Pinky Raigond Brajesh Singh Sundaresha Siddappa Vinay Bhardwaj 《Critical reviews in biotechnology》2017,37(7):942-957
Tuberization in potato (Solanum tuberosum L.) is a complex biological phenomenon which is affected by several environmental cues, genetic factors and plant nutrition. Understanding the regulation of tuber induction is essential to devise strategies to improve tuber yield and quality. It is well established that short-day photoperiods promote tuberization, whereas long days and high-temperatures inhibit or delay tuberization. Worldwide research on this complex biological process has yielded information on the important bio-molecules (proteins, RNAs, plant growth regulators) associated with the tuberization process in potato. Key proteins involved in the regulation of tuberization include StSP6A, POTH1, StBEL5, StPHYB, StCONSTANS, Sucrose transporter StSUT4, StSP5G, etc. Biomolecules that become transported from “source to sink” have also been suggested to be important signaling candidates regulating the tuberization process in potatos. Four molecules, namely StSP6A protein, StBEL5 RNA, miR172 and GAs, have been found to be the main candidates acting as mobile signals for tuberization. These biomolecules can be manipulated (overexpressed/inhibited) for improving the tuberization in commercial varieties/cultivars of potato. In this review, information about the genes/proteins and their mechanism of action associated with the tuberization process is discussed. 相似文献
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Kim MS Kim HS Kim YS Baek KH Oh HW Hahn KW Bae RN Lee IJ Joung H Jeon JH 《Plant cell reports》2007,26(10):1717-1725
A higher concentration of H2O2 was detected in the sense transgenic potato plant (SS4) with the lily chCu,ZnSOD sequence, whereas higher levels of O2− was detected in the antisense transgenic plant (SA1) than the WT plant. The elongation growth in SA1 was significantly inhibited
by treatment with diphenyleneiodonium, an inhibitor of O2− generation, and promoted in the SS4 on treatment with herbicide methyl viologen, a generator of apoplastic O2−. Higher concentrations of GAs were detected during plant growth and the early stage of tuberization in SA1. Complete recovery
of the above elongation growth and microtuberization pattern in transgenic plants following treatment of GA3 or an inhibitor of gibberellin synthesis, paclobutrazol, indicate that these changes were mainly caused by active GA levels.
In conclusion, a specific ROS (O2− ) acts as a signal transducer via GA biosynthetic pathways for the regulation of plant growth and tuber development of potato. 相似文献
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Martin Raspor Václav Motyka Eva ?i?ková Petre I. Dobrev Alena Trávní?ková Sne?ana Zdravkovi?-Kora? Ana Simonovi? Slavica Ninkovi? Ivana C. Dragi?evi? 《Journal of Plant Growth Regulation》2012,31(3):460-470
Genes encoding cytokinin oxidase/dehydrogenase (CKX) enzymes have been used lately to study cytokinin homeostasis in a variety of plant species. In this study AtCKX2-overexpressing potato plants were engineered and grown in vitro as a model system to investigate the effects of altered cytokinin levels on tuber formation and tuber size. Protein extracts from shoots and roots of transformed potato plants exhibited higher CKX activity compared to control plants. Total endogenous cytokinin levels were generally not decreased in AtCKX2 overexpressors. However, levels of bioactive cytokinins were markedly lowered, which was accompanied by increased levels of O- and N-glucosides in some transgenic lines. The AtCKX2-overexpressing plants displayed reduced shoot growth but other symptoms of the ??cytokinin deficiency syndrome?? were not recorded. The transgenic plants were able to produce tubers in noninducing conditions. In inducing conditions they developed larger tubers than control. Tubers were also formed on a greater portion of the analyzed AtCKX2 plants, but with a lower number of tubers per plant compared to control. Taken together, our data suggest that cytokinins cannot be regarded simply as positive or negative regulators of tuberization, at least in vitro. Interactions with other plant hormones that play an important role in control of tuberization, such as gibberellins, should be further studied in detail. 相似文献