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61.
Sandal I Saini U Lacroix B Bhattacharya A Ahuja PS Citovsky V 《Plant cell reports》2007,26(2):169-176
Tea is one of the major crops in Asia and Africa, and its improvement by genetic modification is important for economy of
many tea-producing regions. Although somatic embryos derived from cotyledon explants have been transformed with Agrobacterium, the leaves of several commercially important tea cultivars have remained recalcitrant to transformation, largely due to
bactericidal effect of polyphenols that are exuded by tea leaves in vitro. Moreover, the commonly used polyphenol adsorbents and antioxidants cannot overcome this problem. Leaf explants, however,
are more desirable than cotyledon-derived somatic embryos, especially when it is necessary to further improve a selected elite
and also retain its superior traits. Thus, we developed a procedure for Agrobacterium-mediated genetic transformation of tea leaf explants which is based on the presence of l-glutamine in the co-cultivation medium. We then showed that the transformation process is facilitated via a protective action
of l-glutamine against bactericidal effects of leaf polyphenols without affecting the bacterial virulence (vir) gene expression. 相似文献
62.
Shafi Amrina Gill Tejpal Zahoor Insha Ahuja Paramvir Singh Sreenivasulu Yelam Kumar Sanjay Singh Anil Kumar 《Molecular biology reports》2019,46(2):1985-2002
Molecular Biology Reports - Hydrogen peroxide (H2O2) is known to accumulate in plants during abiotic stress conditions and also acts as a signalling molecule. In this study, Arabidopsis thaliana... 相似文献
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Identification and cross-species amplification of EST derived SSR markers in different bamboo species 总被引:1,自引:0,他引:1
Vikas Sharma Pankaj Bhardwaj Rahul Kumar Ram Kumar Sharma Anil Sood Paramvir Singh Ahuja 《Conservation Genetics》2009,10(3):721-724
The availability of expressed sequence data derived from gene discovery programs became an alternative source of mining simple
sequence repeat (SSR) and developing inexpensive genetic markers for the crop improvements. In present study, 10 express sequence
tags (EST)-SSR markers were identified from Bambusa oldhamii public sequence data base. Transferability to 25 species of Bambusoideae ranged from 30% to 100%. The number of alleles detected
per locus ranged from 2 to 10. All the newly identified SSR markers were found to be moderately to highly polymorphic with
an average Polymorphic Information Content (PIC) value of 0.54. As these loci represents transcribed region and recorded high
level of cross transferability and reliable amplification across the species, demonstrating the utility of these markers for
functional and genetic analyses of bamboo species. 相似文献
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Archana Mathur Ajay Kumar Mathur Arun Kumar Kukreja Paramvir Singh Ahuja Bali Ram Tyagi 《Plant Cell, Tissue and Organ Culture》1987,10(2):129-134
A tissue culture procedure was developed for the establishment and propagation of a colchi-autotetraploid of Rauvolfia serpentina for possible commercial exploitation. Multiplication of autotetraploid shoots was obtained either through axillary bud elongation on Murashige and Skoog [1] medium (MS) containing 2.65 M (0.5 mgl–1) -naphthaleneacetic acid and 0.33 M (0.05 mgl–1) kinetin, or via multiple shoot formation on MS medium supplemented with 4.44 M (1.0 mgl–1) 6-benzylaminopurine and 0.53 M (0.1 mgl–1) -naphthaleneacetic acid. Rooting could be induced by transferring the shoots to MS medium containing 7.95 M (1.5 mgl–1) -naphthaleneacetic acid alone. The plantlets, thus formed, were tetraploid in nature by cytological observations of the root tips. They exhibited 80–90% success in establishment under glass house and field conditions. 相似文献
68.
An efficient liquid culture system for tea shoot proliferation 总被引:3,自引:0,他引:3
Sandal Indra Bhattacharya Amita Singh Ahuja Paramvir 《Plant Cell, Tissue and Organ Culture》2001,65(1):75-80
The efficiency of thidiazuron in promoting tea shoot proliferation in liquid medium was evaluated. As compared to 6-benzyl
adenine which induced hyperhydricity in the proliferated shoots in liquid medium, a progressive increase in the multiplication
rate together with healthy shoot growth was achieved when thidiazuron (2.5 to 5.0 μM) was used instead of 6-benzyl adenine.
Of the different liquid volumes compared in 250 ml Erlenmyer flasks, 20 ml was the most effective. While an increase in the
multiplication rate coupled with normal but healthy shoots was observed under static and agitated conditions at this volume
of liquid medium, hyperhydricity was induced in 50 ml liquid medium. Therefore, 20 ml static liquid medium with subculture
periods at an interval six to eight weeks seems to be a cost and labour effective process as compared to the existing protocols
involving solid media with subculture periods at 4 weeks interval.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
69.
The hypothesis that the relatively large and complex vertebrate genome was created by two ancient, whole genome duplications has been hotly debated, but remains unresolved. We reconstructed the evolutionary relationships of all gene families from the complete gene sets of a tunicate, fish, mouse, and human, and then determined when each gene duplicated relative to the evolutionary tree of the organisms. We confirmed the results of earlier studies that there remains little signal of these events in numbers of duplicated genes, gene tree topology, or the number of genes per multigene family. However, when we plotted the genomic map positions of only the subset of paralogous genes that were duplicated prior to the fish–tetrapod split, their global physical organization provides unmistakable evidence of two distinct genome duplication events early in vertebrate evolution indicated by clear patterns of four-way paralogous regions covering a large part of the human genome. Our results highlight the potential for these large-scale genomic events to have driven the evolutionary success of the vertebrate lineage. 相似文献
70.
The host range specificity ofAgrobacterium with five tea cultivars and an unrelated species (Artemisia parviflora) having extreme surface characteristics was evaluated in the present study. The degree ofAgrobacterium infection in the five cultivars of tea was affected by leaf wetness, micro-morphology and surface chemistry. Wettable leaf
surfaces of TV1, Upasi-9 andKangra jat showed higher rate (75%) ofAgrobacterium infection compared to Upasi-10 and ST-449, whereas non-wettable leaves ofA. parviflora showed minimum (25%) infection. This indicated that the leaves with glabrous surface having lower 8 (larger surface area
covered by water droplet), higher phenol and wax content were more suitable forAgrobacterium infection. Caffeine fraction of tea promotedAgrobacterium infection even in leaves poor in wax (Upasi-10), whereas caffeine-free wax inhibited bothAgrobacterium growth and infection. Thus, study suggests the importance of leaf surface features in influencing theAgrobacterium infection in tea leaf explants. Our study also provides a basis for the screening of a clone/cultivar of a particular species
most suitable forAgrobacterium infection the first step inAgrobacterium-mediated genetic transformation. 相似文献