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Genetic variation in rooting ability of loblolly pine cuttings: effects of auxin and family on rooting by hypocotyl cuttings 总被引：1，自引：0，他引：1
After about 20 days, hypocotyl cuttings from 20-day-old loblolly pine (Pinus taeda L.) seedlings rooted easily in the presence of the auxin indole-3-butyric acid (IBA), with roots forming directly from xylem parenchyma. In contrast, woody cuttings from 1-2-year-old hedged seedlings formed roots indirectly from callus tissue in 60-90 days, but IBA had little effect on rooting. Variation in rooting among hypocotyls from both half- and full-sib families was highly significant in response to IBA, and rooting did not occur within 20 days unless IBA was applied. Hypocotyls from poor rooting families tended to produce fewer roots per cutting than hypocotyls from good rooting families. Rooting by woody cuttings and hypocotyl cuttings from the same nine full-sib families was weakly correlated, raising the possibility that at least some common genetically controlled processes were affecting rooting by both types of cutting. The phytotropin N-1-naphthylphthalamic acid (NPA), supplied at 1 micro M with 10 micro M IBA, significantly inhibited rooting by hypocotyl cuttings from both good and poor rooting families, but there was no significant family x treatment interaction. Family variation in rooting ability may be a function of the frequency of occurrence of auxin-responsive cells in the hypocotyls. 相似文献
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Cuttings from mature chestnut (Castanea spp.) trees are very difficult to root, whereas juvenile or etiolated cuttings root easily. The HPLC chromatograms from mature cuttings consistently showed two well-defined peaks that were absent from juvenile or etiolated cuttings. The compounds responsible for these two peaks were isolated and identified as derivatives of ellagic acid, 3,3',4-tri-O-methylellagic acid (compound 1) and 3,4,4'-tri-O-methylellagic acid (compound II). Compound I significantly inhibited rooting as measured by the bean test; a concentration of 3.0 x 10(-5) M caused a 32% inhibition in number of roots formed compared with controls grown in 10(-5) M IAA. When compound I was mixed with an equal quantity of IAA, the rooting activity of the auxin was reduced by 31.5%. An insufficient amount of compound II was available for the bean assay. 相似文献
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Two SCARECROW-LIKE genes are induced in response to exogenous auxin in rooting-competent cuttings of distantly related forest species 总被引：4，自引：0，他引：4
Sánchez C Vielba JM Ferro E Covelo G Solé A Abarca D de Mier BS Díaz-Sala C 《Tree physiology》2007,27(10):1459-1470
We characterized SCARECROW-LIKE genes induced by auxin in rooting-competent cuttings of two distantly related forest species (Pinus radiata D. Don and Castanea sativa Mill.) before the activation of cell division that results in adventitious root formation. The predicted protein sequences contain domains characteristic of the GRAS protein family and show a strong similarity to the SCARECROW-LIKE proteins, indicating conserved functions of these proteins. Quantitative RT-PCR analysis showed that these genes are expressed at relatively high levels in roots. Induction of increased mRNA levels in rooting-competent cuttings of both species in response to exogenous auxin was observed within the first 24 h of the root induction process, a time when cell reorganization takes place, but before the resumption of cell division and the appearance of adventitious root primordia. These results suggest that SCARECROW-LIKE genes play a role during the earliest stages of adventitious root formation. 相似文献
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生长素对楸树不定芽的诱导和增殖培养影响的研究 总被引：1，自引：0，他引：1
以楸树无菌苗茎段为材料,研究了不同生长素（NAA、IAA、IBA、2,4-D）在不同浓度下（0．05、0．1、0．2mg／L）对不定芽诱导、增殖和生根的影响。结果表明：在添加IAA激素的培养基中,不定芽的诱导生长最好。IAA0．1mg／L和6-BA0．8mg／L纽合不定芽诱导率高达100％,而且生长健壮;在NAA0．1mg／L和6-BA2．0mg／L的培养基中,IAA0．1mg／L和6-BA0．8mg／L组合诱导出的不定芽增殖倍数最高,为3．23,且不定芽健壮;添加I从0．Img／L对不定芽的生根也有利。 相似文献
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The hormonal control of stem unit (foliar appendage and axillary structure, if present, plus subtending internode) number and length was investigated in shoots of Scots pine (Pinus sylvestris L.) and white spruce (Picea glauca (Moench) Voss). Seedlings were treated with six gibberellins (GA1, GA3, GA4, GA5, GA9 and GA20) and two auxins (indole-3-acetic acid (IAA) and naphthaleneacetic acid (NAA)) when either neoformed growth was occurring or the terminal vegetative bud was developing. Hormones were applied by drenching the shoot tip, injecting the stem or spraying the foliage. Combined results for all three application methods indicated that shoot elongation in first-year seedlings (i.e., neoformed growth) was promoted in both species by GA1, GA3, GA4 and, less obviously, by GA9. This promotion was attributable to an increase in length, rather than number, of stem units. However, the number of stem units formed during terminal bud development, as reflected in the number of needles (white spruce) or cataphylls (Scots pine) present on the shoot resulting from the terminal bud, was stimulated by GA1, GA3 and GA4 in both species and by GA9 in Scots pine. The GA-induced increase in the number of preformed stem units was associated with increased bud width in white spruce and increased bud length and resulting shoot length in Scots pine. In contrast, application of IAA or NAA either did not affect or inhibited both neoformed growth and terminal bud stem unit number, depending on the application method and concentration. We conclude that, in the Pinaceae, (1) GA stimulates the activity of both the subapical meristem during neoformed growth and the apical meristem during vegetative bud development, and (2) the early non-hydroxylation pathway, via GA9, is the major route of GA biosynthesis. The role of auxin in the control of stem unit number and length remains to be resolved. 相似文献
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We studied the ability of the ectomycorrhizal (ECM) fungi, Pisolithus tinctorius (Pers.) Coker and Couch and Paxillus involutus (Batsch) Fr. (Strain H), to produce indole-3-acetic acid (IAA) and to affect the formation and growth of roots on Scots pine (Pinus sylvestris L.) hypocotyl cuttings in vitro. Effects of indole-3-butyric acid (IBA) and the auxin transport inhibitor, 2,3,5-triiodobenzoic acid (TIBA), on rooting and the cutting-fungus interaction were also studied. Both fungi produced IAA in the absence of exogenous tryptophan, but the mycelium and culture filtrate of Pisolithus tinctorius contained higher concentrations of free and conjugated IAA than the mycelium and culture filtrate of Paxillus involutus. Inoculation with either fungus or short-term application of culture filtrate of either fungus to the base of hypocotyl cuttings enhanced root formation. Inoculation with either fungus was even more effective in enhancing root formation than treatment of the hypocotyl bases with IBA. Fungal IAA production was not directly correlated with root formation, because rooting was enhanced more by Paxillus involutus than by Pisolithus tinctorius. This suggests that, in addition to IAA, other fungal components play an important role in root formation. Treatment with 5 microM TIBA increased the rooting percentage of non-inoculated cuttings, as well as of cuttings inoculated with Pisolithus tinctorius, perhaps as a result of accumulation of IAA at the cutting base. However, the marked reduction in growth of Pisolithus tinctorius in the presence of TIBA suggests that the effects of TIBA on rooting are complicated and not solely related to IAA metabolism. The high IAA-producer, Pisolithus tinctorius, formed mycorrhizas, and the IBA treatment increased mycorrhizal frequency in this species, whereas TIBA decreased it. Paxillus involutus did not form mycorrhizas, indicating that a low concentration of IAA together with other fungal components were sufficient to stimulate formation and growth of the roots, but not the formation of ECM symbiosis. 相似文献
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The ectomycorrhizal fungus Laccaria bicolor S238 N and the bacterium Pseudomonas fluorescens BBc6 were used separately and in combination to induce in vitro rooting of de-rooted shoot hypocotyls of Norway spruce (Picea abies (L.) Karst.). When the culture medium was supplemented with tryptophan, a precursor of indole-3-acetic acid (IAA) synthesis, the presence of the ectomycorrhizal fungus increased the percentage of hypocotyls forming roots; furthermore, both the fungal and bacterial inoculations enhanced the number of roots formed per rooted hypocotyl. Similar results were obtained by adding exogenous IAA (5 and 10 &mgr;M) to the rooting medium. After the rooting phase, the fungal inoculation enhanced adventitious root elongation and branching as well as the aerial growth of the cuttings. Pseudomonas fluorescens BBc6 had no effect on these parameters. The production of IAA by pure cultures of L. bicolor S238 N and P. fluorescens BBc6 was estimated by immunochemical analysis using specific anti-IAA antibodies. Both L. bicolor S238 N and P. fluorescens BBc6 synthesized IAA in pure culture and synthesis was stimulated in the presence of tryptophan. Thus, the effect of the fungus in stimulating adventitious root formation and subsequent elongation and branching can be attributed, at least partially, to the synthesis of IAA by the fungus. The finding that P. fluorescens BBc6 had no effect on root elongation and branching although it produced IAA suggests that either IAA was not the only parameter involved in the stimulation of these processes by L. bicolor S238 N or the bacterium produced other compounds that counteracted the stimulatory effects of IAA on root elongation and branching. 相似文献
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Genetic transformation of loblolly pine using mature zygotic embryo explants by Agrobacterium tumefaciens 总被引：1，自引：0，他引：1
Introduction1Genetictransformationinconifershasthepotentialtoallowtheselectiveimprovementofindividualtraitsinelitecloneswhilestillmaintainingtheexistingcombinationofgenesresponsibleforthesuperiorphenotype(Charestetal.1991;Jamesetal.1996;Walteretal.1999).Atpresent,althoughconsiderableresearchefforthasbeendevotedtothegeneticengineeringofconiferspecies(Sederoffetal.1986;Bekkauoietal.1988,1990;Robertsonetal.1992;Bomminenietal.1993;Shinetal.1994;Klimaszewskaetal.1997),ithaslaggedbehindadvancesma… 相似文献
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Auxin polar transport genes PIN(PINFORMED)determine the concentration gradient of auxin in plants.To understand the relationship between the development of different tissues in Betula pendula‘Dalecartica’,BpPIN gene expression and indole-3-acetic acid(IAA)content were analyzed using qRT-PCR,ELISA,and GUS staining.Gene expression of BpPIN genes and IAA levels in the leaves,buds,stems,xylem,and roots of B.pendula‘Dalecartica’and B.pendula as a control were measured.BpPIN1,BpPIN5 and BpPIN6 were upregulated during development in both species,suggesting a dominant role in the development of B.pendula‘Dalecartica’leaves.Moreover,BpPIN1 gene expression was positively associated with IAA levels during leaf,vein and petiole development in B.pendula‘Dalecartica’only.The correlation coefficient of the first three leaves was 0.69(P=0.04),while that of the first three petioles was 0.85(P=0.001).In addition,GUS staining of the pro-DR5::GUS transgenic line of cultivar was correlated with the results of BpPIN1 expression.Overall,these findings suggest that BpPIN1 is associated with the formation of lobed leaves in B.pendula‘Dalecartica’. 相似文献
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Agrobacterium tumefaciens strain LBA 4404 carrying pBI121 plasmid was used to transform mature zygotic embryos of three genotypes (E-Hb, E-Ma, and
E-Mc) of loblolly pine. The results demonstrated that the expression frequency of β-glucuronidase reporter gene (GUS) varied
among genotypes after mature zygotic embryos were infected withAgrobacterium tumefaciens cultures. The highest frequency (27.8%) of GUS expressing embryos was obtained from genotype E-Mc with mean number of 21.9
blue GUS spots per embryo. Expression of β-glucuronidase reporter gene was observed on cotyledons, hypocotyls, and radicles
of transformed mature zygotic embryos, as well as on organogenic callus and regenerated shoots derived from co-cultivated
mature zygotic embryos. Nineteen regenerated transgenic plants were obtained from GUS expression and kanamycin resistant calli.
The presence and integration of the GUS gene was confirmed by polymerase chain reaction (PCR) and Southern blot analysis.
These results suggested that an efficientAgrobacterium tumefaciens-mediated transformation protocol for stable integration of foreign genes into loblolly pine has been developed and that this transformation
system could be useful for the future studies on transferring economically important genes to loblolly pine. 相似文献
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The level of indole-3-acetic acid (IAA) in shortleaf pine (Pinus echinata Mill.) roots was increased by inoculation with the ectomycorrhizal fungus Pisolithus tinctorius (Pers.) Coker and Couch. Indole-3-acetic acid oxidase activity was also increased suggesting that the increased level of IAA was the result of increased synthesis. Boron fertilization reduced IAA levels in roots inoculated with P. tinctorius but not in noninoculated roots. 相似文献
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We determined whether in vitro plant growth regulator production by mycorrhizal fungi is correlated with conifer seedling growth and root IAA concentrations. Container-grown seedlings of interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), lodgepole pine (Pinus contorta Dougl.) and ponderosa pine (Pinus ponderosa Dougl.) were inoculated at seeding with ectomycorrhizal fungi having a high, moderate or low capacity to produce either IAA or ethylene in vitro. Inoculated seedlings were grown for one season in the nursery, harvested in December, cold stored over winter and then transplanted to either a nursery field or a forest site in the spring. Seedling morphology and endogenous IAA in roots were measured immediately after cold storage and again six and 12 months after transplanting. Morphological responses to inoculation varied among different mycorrhizal fungi. Free IAA concentration of roots was increased in some inoculation treatments for all conifer species. In seedlings transplanted to a nursery field, in vitro ethylene-producing capacity of the ectomycorrhizal fungi was highly correlated with more morphological features than in vitro IAA-producing capacity. Both IAA- and ethylene-producing capacity were significantly correlated with more morphological features in seedlings transplanted to a forest site than in seedings transplanted to a nursery field. One year after transplanting, only in vitro IAA-producing capacity was correlated with endogenous IAA concentration of roots of the inoculated seedlings. We conclude that growth responses of conifer seedlings can be partially influenced by IAA and ethylene produced by ectomycorrhizal fungal symbionts. 相似文献
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