20 research outputs found
Detection of self-complementary inverted repeats by single forward primer driven PCR
Inverted repeat gene structures designed for silencing functional genes have been widely used both in academic and applied research. The correct orientations of such structures are usually validated with restriction analysis and/or sequencing. We speculated that the
inverted repeat nature of such constructs can be shown by a simple PCR reaction with a single forward primer. To test this hypothesis five different constructs were established from grapevine sequences in a hairpin-intron style silencing system. We were able to amplify the appropriate products in each case. Thus a forward-primed PCR alone may be sufficient to prove the inverted repeat nature of the desired constructs
Detection of self-complementary inverted repeats by single forward primer driven PCR
Inverted repeat gene structures designed for silencing functional genes have been widely used both in academic and applied research. The correct orientations of such structures are usually validated with restriction analysis and/or sequencing. We speculated that the inverted repeat nature of such constructs can be shown by a simple PCR reaction with a single forward primer. To test this hypothesis five different constructs were established from grapevine sequences in a hairpin-intron style silencing system. We were able to amplify the appropriate products in each case. Thus a forward-primed PCR alone may be sufficient to prove the inverted repeat nature of the desired constructs
Agrobacterium vitis strains lack tumorigenic ability on in vitro grown grapevine stem segments
Grapevine stem segments were cocultivated with
three different Agrobacterium tumefaciens and three
different A. vitis strains. A. tumefaciens strains induced
tumors at variable frequencies, while A. vitis-infected
stem segments never formed crown galls. The tumorous
nature of tissues grown on hormone free medium was confirmed by opine assays. Bioinformatic and PCR
analysis of the virulence regions of various A. tumefaciens and A. vitis Ti plasmids showed that virH2 and
virK genes are common in A. tumefaciens but they are
lacking from A. vitis. Thus virH2 and virK genes may be
essential for grapevine stem segment transformation,
but expression of certain T-DNA genes of A. vitis may
also prevent the growth of transformed cells. Our data
indicate that the tumorigenic ability of A. vitis is different
on intact plant and on their explants, and that
the specific host association of A. vitis on grapevine is
probably determined by physiological and biochemical
factors (e. g., better colonizing ability) rather than
by its increased tumorigenic ability. Therefore it is not
reasonable to develop „helper” plasmids for grapevine
transformation from A. vitis pTis, unless their
avirulence on in vitro explants is determined by T-DNA
gene(s). Due to the inability of A. vitis to induce tumors
on grapevine stem segments, the use of in vitro explant
assays cannot be reliably used to select A. vitis resistant
grapevine genotypes or transgenic lines
A ferritin szerepe a szőlő stressztűrő képességének fokozásában = The role of ferritin in enhancing the stress tolerance of grapevine
EmbriogĂ©n kalluszt állĂtottuk elĹ‘ Richter110 (alany) Ă©s Chardonnay (nemes) szĹ‘lĹ‘ fajták portokajibĂłl. Ezeket Medicago sativa ferritint (MsFerr) tartalmazĂł Agrobacterium vektorokkal transzformáltunk. A DNS beĂ©pĂĽlĂ©sĂ©t genomikus PCR-rel ellenĹ‘riztĂĽk. Poliklonális ellenanyagot állĂtottunk elĹ‘, mellyel megállapĂtottuk, hogy a transzláciĂł magas szintű volt, a transzkriptumbĂłl nagy mennyisĂ©gű, megfelelĹ‘en processzált fehĂ©rjetermĂ©k keletkezett. A transzgenikus szĹ‘lĹ‘ növĂ©nyek elkĂ©szĂĽltĂ©ig dohányban teszteltĂĽk az MsFerr gĂ©nt tartalmazĂł konstrukciĂłkat. A teljes növĂ©nyeken vĂ©gzett UV-B kezelĂ©s, ill. levĂ©lkorongok közvetlen oxidatĂv stresszre adott válaszai alapján megállapĂtottuk, hogy az MsFerr növĂ©nyek toleránsabbak voltak, mint a nem expresszálĂł kontrollok. Az MsFerr Richter 110 növĂ©nyek regenerálása, szelekciĂłja Ă©s felszaporĂtása sikeres volt, az MsFerr Chardonnay növĂ©nyek felszaporĂtása azonban hajtásnövekedĂ©si problĂ©mák miatt nem sikerĂĽlt. Három MsFerr Richter 110 vonalat vizsgáltunk. GyökĂ©r stresszkĂ©nt fás szárĂş dugványok tápoldatához hidrogĂ©nkarbonátot adtunk, ami klorotikus Ă©s levĂ©l száradási tĂĽnetek okozott Ebben nem kaptunk lĂ©nyeges kĂĽlönbsĂ©get a transzgenikus Ă©s transzformálatlan növĂ©nyek között. Ezzel szemben, a leveleket Ă©rĹ‘ hatásokkal: paraquat, NaCl sĂł-stressz Ă©s tBHP indukált lipid peroxidáciĂłval szemben az MsFerr expresszálĂł vonalak toleránsabbak voltak (kisebb stressz-indukált fotoszintĂ©zis csökkenĂ©st mutattak) mint a transzformálatlanok. | Embryogenic calli were started from anthers of Richter 110 (rootstock) and Chardonnay (scion) grapevine and transformed with Agrobacterium harbouring Medicago sativa ferritin gene (MsFerr). Genomic PCR and protein immunoblotting using a polyclonal antibody confirmed that the transcription and processing of MsFerr was successful. Regeneration, selection and propagation of MsFerr Richter 110 plants was successful, but transformed MsFerr Chardonnay plants did not grow sufficiently. Until transgenic grapevine plants became available, preliminary experiments were carried out with MsFerr expressing tobacco. UV-B irradiation of whole plants as well as treatments of leaf disks with various chemical elicitors showed that MsFerr plants were more stress tolerant than non-expressing controls. After regeneration and propagation, three transgenic MsFerr Richter 110 lines were tested. Roots of green cuttings were stressed by flooding and in this experiment transgenic plants did not show significantly higher tolerance to hypoxia/bicarbonate than non-transferred ones. Leaves, however, showed increased tolerance to paraquat, salt stress and tBHP induced lipid peroxidation: their photosynthesis was less affected by these stressors than those from non-transformed plants
Candidate plant gene homologues in grapevine involved in Agrobacterium transformation
Abstract
The grapevine (Vitis vinifera) genome was analyzed in silico for homologues of plant genes involved in Agrobacterium transformation in Arabidopsis thaliana and Nicotiana spp. Grapevine homologues of the glucomannan 4-betamannosyltransferase 9 gene CslA-09 involved in bacterial attachment to the cell wall, homologues of reticulon-like proteins BTI1, 2, 3 and RAB8 GTPases, both involved in T-DNA transfer to the host cell, homologues of VirE2 interacting protein VIP1 that contributes to the targeting of T-DNA into the nucleus and to its integration, and homologues of the histone protein H2A, which promotes the expression of T-DNA encoded genes, were selected. Sequences homologous to the arabinogalactan-protein AtAGP17 were not found in the grape genome. Seventeen selected candidates were tested by semiquantitative RT-PCR analysis for changes in their expression levels upon inoculation with Agrobacterium tumefaciens C58. Of the tested homologues, the expression of VvRab8a, VvVip1a and two histone genes (VvHta2 and VvHta10) increased significantly, therefore we hypothesize that these might be involved in Agrobacterium transformation of V. vinifera.</jats:p
Quorum-sensing signal production by Agrobacterium vitis strains and their tumor-inducing and tartrate-catabolic plasmids
Agrobacterium vitis strains, their tumor-inducing (pTi) and tartrate utilization (pTr) plasmid transconjugants and grapevine tumors were analyzed for the presence of N-acyl-homoserine lactones (AHLs). All wild-type A. vitis strains produced long-chain signals. PCR analysis of the A. vitis long-chain AHL synthase gene, avsI, showed the predicted amplicon. Agrobacterium tumefaciens UBAPF2 harboring various A. vitis pTi plasmids produced N-(3-oxo-octanoyl)-l-homoserine lactone encoded also by pTis of A. tumefaciens. UBAPF2 transconjugants carrying pTrs except for pTrTm4 and pTrAB3, also produced an AHL. UBAPF2 transconjugants carrying pTrAT6, pTrAB4 and pTrRr4 or pTiNi1 produced two additional AHLs not observed in the corresponding wild-type strains. We also provide evidence for in situ production of AHLs in grapevine crown gall tumors of greenhouse and field origi
Culture media supplemented with inorganic salts improve the growth and viability of several bacterial strains
In order to improve growth and storage conditions for bacterial cultures, commonly used basic culture media, Luria-Bertani broth (LB) and glucose-yeast extract (GY) were
tested along with their supplemented versions (LBS and GYS) containing a complex set of inorganic salts required for common physiological processes. The growth kinetics and viability of 15 representative strains were compared on LB/LBS or GY/GYS. Growth kinetics were examined during a 24 h period. Five out of 15 strains showed enhanced growth on LBS and GYS. Three strains showed very low viability (3 months or lower) both on the basic and salt-supplemented media. Six strains could be equally recovered after 6 or 12 months both from LB/LBS and from GY/GYS. Six of the tested 15 bacterial strains showed significantly better recovery rate on the inorganic-supplemented media LBS or GYS than on basic LB or GY. These results show that inorganic supplement of basic media may significantly improve the growth and viability of several bacterial strains
Culture media supplemented with inorganic salts improve the growth and viability of several bacterial strains
In order to improve growth and storage conditions for bacterial cultures, commonly used basic culture media, Luria-Bertani broth (LB) and glucose-yeast extract (GY) were
tested along with their supplemented versions (LBS and GYS) containing a complex set of inorganic salts required for common physiological processes. The growth kinetics and viability of 15 representative strains were compared on LB/LBS or GY/GYS. Growth kinetics were examined during a 24 h period. Five out of 15 strains showed enhanced growth on LBS and GYS. Three strains showed very low viability (3 months or lower) both on the basic and salt-supplemented media. Six strains could be equally recovered after 6 or 12 months both from LB/LBS and from GY/GYS. Six of the tested 15 bacterial strains showed significantly better recovery rate on the inorganic-supplemented media LBS or GYS than on basic LB or GY. These results show that inorganic supplement of basic media may significantly improve the growth and viability of several bacterial strains