Improved procedures for in vitro regeneration and for phenotypic analysis in the model legume Lotus japonicus

2005 ◽  
Vol 32 (6) ◽  
pp. 529 ◽  
Author(s):  
Ani Barbulova ◽  
Enrica D'Apuzzo ◽  
Alessandra Rogato ◽  
Maurizio Chiurazzi

As a prerequisite for the development of an efficient gene transfer methodology, the possibility of inducing direct somatic embryogenesis in Lotus japonicus (Regel) K. Larsen explants was investigated. Petiole bases, cotyledons, hypocotyls and stem segments were cultivated in the presence of different amounts of benzylaminopurine (BAP) and / or thidiazuron (TDZ). Regeneration was achieved differentially in the different explants and a higher efficiency of shoot formation was obtained with TDZ. By maintaining the same TDZ regime a second cycle of morphogenesis was achieved and the histological analysis of these structures indicated unambiguously their somatic embryogenic nature. Thidiazuron was also tested as an agent to improve the kinetics of shoot formation in a Lotus japonicus transformation–regeneration procedure based on indirect organogenesis. A very significant, highly reproducible, increase in the rate of the shoot formation was observed in independent transformation experiments. We also present an extensive analysis of the feasibility and reproducibility of an in vitro procedure, which can be very useful for the screening of symbiotic phenotypes in transgenic Lotus plants and for the analysis of the cascade of molecular and cytological events occurring soon after Mesorhizobium loti infection.

2003 ◽  
Vol 16 (4) ◽  
pp. 281-288 ◽  
Author(s):  
Tomomi Nakagawa ◽  
Tomoko Izumi ◽  
Mari Banba ◽  
Yosuke Umehara ◽  
Hiroshi Kouchi ◽  
...  

Phosphoenolpyruvate carboxylases (PEPCs), one form of which in each legume species plays a central role in the carbon metabolism in symbiotic root nodules, are activated through phosphorylation of a conserved residue by a specific protein kinase (PEPC-PK). We characterized the cDNAs for two PEPC isoforms of Lotus japonicus, an amide-translocating legume that forms determinate nodules. One gene encodes a nodule-enhanced form, which is more closely related to the PEPCs in amide-type indeterminate nodules than those in ureide-type determinate nodules. The other gene is expressed in shoots and roots at a low level. Both forms have the putative phosphorylation site, Ser11. We also isolated a cDNA and the corresponding genomic DNA for PEPC-PK of L. japonicus. The recombinant PEPC-PK protein expressed in Escherichia coli phosphorylated recombinant maize C4-form PEPC efficiently in vitro. The level of mRNA for PEPC-PK was high in root nodules, and those in shoots and roots were also significant. In situ hybridization revealed that the expression patterns of the transcripts for PEPC and PEPC-PK were similar in mature root nodules, but were different in emerging nodules. When L. japonicus seedlings were subjected to prolonged darkness and subsequent illumination, the activity of PEPC-PK and the mRNA levels of both PEPC and PEPC-PK in nodules decreased and then recovered, suggesting that they are regulated according to the amounts of photosynthates transported from shoots.


2017 ◽  
Vol 4 (2) ◽  
pp. 52-56
Author(s):  
Mallika Devi T

In the present study the protocol for callus induction and regeneration in Azima tetracantha has been developed in culture medium. The young apical leaf explants were used for callus induction on MS medium containing BAP and NAA at 1.0 and 0.4mgl-1 respectively showed maximum callus induction (73%). The amount of callus responded for shoot formation (74%) was obtained in the MS medium containing BAP (1.5 mgl-1) and NAA (0.3mgl-1).The elongated shoots were rooted on half strength medium supplemented with IBA (1.5 mgl-1) and Kn (0.4 mgl-1) for shoots rooted. Regenerated plantlets were successfully acclimatized and hardened off inside the culture and then transferred to green house with better survival rate.


1970 ◽  
Vol 18 (2) ◽  
pp. 173-179 ◽  
Author(s):  
T. Mallikadevi ◽  
P. Senthilkumar ◽  
S. Paulsamy

The in vitro regeneration of Plubago zeylanica exhibited that the callus was initiated in the basal medium containing BAP, NAA, 2, 4-D, and IBA.  The high amount (90%) of organic calli was induced in the basal medium supplemented with 2, 4-D, alone at 2.0 mg/l. In the subculture the adventitious shoot formation was prominently higher (83%) in the basal medium containing BAP, and NAA at 3.5 and 0.3 mg/l, respectively. IAA (1.0 mg/l)effectively produced higher percen-tage (90) of roots and root growth. After sequential hardening, survivability rate was observed to be significantly higher (80%) in the hardening medium containing garden soil, sand and vermicompost in the ratio of 1 : 1 : 1 by volume under greenhouse condition.  Key words: Plumbago zeylanica, In vitro regeneration, Medicinal plant D.O.I. 10.3329/ptcb.v18i2.3648 Plant Tissue Cult. & Biotech. 18(2): 173-179, 2008 (December)


Plants ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 178 ◽  
Author(s):  
Sabbadini ◽  
Ricci ◽  
Limera ◽  
Baldoni ◽  
Capriotti ◽  
...  

Prunus spp. is one of the most recalcitrant fruit tree species in terms of in vitro regeneration and transformation, mostly when mature tissues are used as explants. The present study describes the in vitro regeneration via indirect organogenesis, and Agrobacterium tumefaciens-mediated transformation of the peach rootstock Hansen 536 (Prunus persica × Prunus amygdalus) through the use of meristematic bulks (MBs) as starting explants. Efficient adventitious shoot regeneration was obtained when Hansen 536 MBs were cultured on an optimized medium consisting of modified McCown Woody Plant medium (WPM) enriched with 4.4 M 6-Benzyladenine (BA), 0.1 M 1-Naphthaleneacetic acid (NAA) and 6.0 g L−1 plant agar S1000 (B&V). MB slices were used later as starting explants for Agrobacterium-mediated transformation to introduce an RNAi construct “ihp35S-PPV194” against PPV virus. Transgenic events were identified by both green fluorescent protein (GFP) screening and kanamycin selection at different concentrations (0, 17 or 42 M). GFP-fluorescent proliferating callus lines were selected and confirmed to stably express the ihp35S-PPV194::eGFP gene construct by molecular analysis. Although shoot regeneration from these transgenic calli has not been obtained yet, this represents one of the few examples of successful attempts in peach genetic transformation from somatic tissues, and also serves as a useful in vitro system for future gene functional analysis in peach.


2016 ◽  
Vol 4 (5) ◽  
Author(s):  
Yoshikazu Shimoda ◽  
Hideki Hirakawa ◽  
Shusei Sato ◽  
Kazuhiko Saeki ◽  
Makoto Hayashi

Mesorhizobium loti is the nitrogen-fixing microsymbiont for legumes of the genus Lotus . Here, we report the whole-genome sequence of a Mesorhizobium loti strain, TONO, which is used as a symbiont for the model legume Lotus japonicus . The whole-genome sequence of the strain TONO will be a solid platform for comparative genomics analyses and for the identification of genes responsible for the symbiotic properties of Mesorhizobium species.


2004 ◽  
Vol 186 (8) ◽  
pp. 2439-2448 ◽  
Author(s):  
Toshiki Uchiumi ◽  
Takuji Ohwada ◽  
Manabu Itakura ◽  
Hisayuki Mitsui ◽  
Noriyuki Nukui ◽  
...  

ABSTRACT Rhizobia are symbiotic nitrogen-fixing soil bacteria that are associated with host legumes. The establishment of rhizobial symbiosis requires signal exchanges between partners in microaerobic environments that result in mutualism for the two partners. We developed a macroarray for Mesorhizobium loti MAFF303099, a microsymbiont of the model legume Lotus japonicus, and monitored the transcriptional dynamics of the bacterium during symbiosis, microaerobiosis, and starvation. Global transcriptional profiling demonstrated that the clusters of genes within the symbiosis island (611 kb), a transmissible region distinct from other chromosomal regions, are collectively expressed during symbiosis, whereas genes outside the island are downregulated. This finding implies that the huge symbiosis island functions as clustered expression islands to support symbiotic nitrogen fixation. Interestingly, most transposase genes on the symbiosis island were highly upregulated in bacteroids, as were nif, fix, fdx, and rpoN. The genome region containing the fixNOPQ genes outside the symbiosis island was markedly upregulated as another expression island under both microaerobic and symbiotic conditions. The symbiosis profiling data suggested that there was activation of amino acid metabolism, as well as nif-fix gene expression. In contrast, genes for cell wall synthesis, cell division, DNA replication, and flagella were strongly repressed in differentiated bacteroids. A highly upregulated gene in bacteroids, mlr5932 (encoding 1-aminocyclopropane-1-carboxylate deaminase), was disrupted and was confirmed to be involved in nodulation enhancement, indicating that disruption of highly expressed genes is a useful strategy for exploring novel gene functions in symbiosis.


Author(s):  
R. Abinaya

In this present work, an in-vitro regeneration protocol for Crescentia alata (C. alata) was developed using various explants on Murashige and Skoog (MS) medium augmented with different concentrations and combinations of plant growth regulators (PGRs) for direct and indirect regeneration. The direct organogenesis was established from nodes and internodes on MS medium supplemented with cytokinins and auxins. The indirect organogenesis via callus phase was obtained from leaf, nodes and internodes on MS medium supplemented with different concentrations of PGRs. The high frequency shoot organogenesis were achieved directly from nodal explants were cultured on MS medium supplemented with 3.0 mg/L BAP+0.5 mg/L KIN +1.0 mg/L NAA. Indirect organogenesis callogenic frequency was optimized at the concentration of MS medium containing 1.0 mg/L BAP + 5.0 mg/L IAA. The callus was obtained from all the explants were used, among these explants internodal explants gave best result on MS medium supplemented with different concentrations of cytokinins and auxins for indirect organogenesis experiment. Indirect organogenesis the highest number of shoot regeneration was obtained in MS Basal Medium with 4.0 mg/L BAP + 0.5 mg/L KIN + 2.0 mg/L NAA from internodal explants. For root formation the regenerative shoots which were sub cultured on MS medium containing different ratios of auxins. The rooted plantlets were transferred successfully to the pots containing sterilized soil and were successfully hardened at greenhouse condition for 20 days then exposed to the natural environment. This is the first successful micropropagation report of an efficient and rapid in-vitro clonal propagation protocol for C. alata by direct and indirect shoot organogenesis through various explants, which can be employed for conservation of this important medicinal tree species as well as the utilization of an biologically important active biomolecules. This protocol can be very useful to obtain plants from various explants, without the requirement of meristematic regions, enabling the obtainment of a higher number of plants in short period.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 873G-874
Author(s):  
D. Sankhla ◽  
T.D. Davis ◽  
N. Sankhla ◽  
A. Upadhyaya

This report describes an efficient in vitro regeneration protocol for H. patens (firebush), a heat-tolerant ornamental shrub native to tropical and subtropical America. Shoot cultures were initially established using shoot tips placed on MS-revised medium containing 2.3 μM 2,4-D, 2.3 μM kinetin, and 0.25% polyvinylpyrrolidone. Other types of explants (nodal and internodal segments, leaf pieces, floral buds) did not regenerate shoots when placed on this medium. Two-month-old plantlets derived from the shoot tips were subcultured on MS medium supplemented with 0.5 μM thidiazuron (TDZ), and within 3 to 4 weeks, some callus was produced at the root–shoot junction. When this callus, with a small portion of the root and shoots, was placed on MS medium with 0.05 μM TDZ and 0.01 μM ABA, prolific shoot formation occurred within 3 to 4 weeks followed by root formation. By regular subculturing every 5 to 6 weeks, hundreds of plantlets have been obtained over the past 3 years with no apparent decline in regeneration potential. Addition of activated charcoal (0.5%) to the culture medium has greatly improved growth of the plantlets.


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