SKM's published research papers
Títle: Characterization of two proteinase inhibitor (ATI) cDNAs from
alfalfa leaves (Medicago sativa var. Vernema): the expression of ATI
genes in response to wounding and soil microorganisms.
Author: McGurl B;
Mukherjee S K; Kahn M; Ryan CA
Institute of Biological Chemistry, Washington State University,
Pullman 99164-6340, USA.
Published in: Plant Mol Biol; 27(5):995-1001, 1995 Mar.
cDNAs encoding two Bowman-Birk proteinase inhibitors were
isolated from the leaves of alfalfa (Medicago sativa). The cDNAs are
derived from a small gene family (3 to 10 genes) encoding alfalfa
trypsin inhibitors (ATIs). Each cDNA clone encoded a mature ATI that
was part of a larger, putative preprotein. ATI mRNAs are continuously
expressed in flower parts, but are mechanically wound-inducible in the stems and leaves. ATI mRNA is shown to be continuously present in roots of soil-grown plants, but its presence is primarily in response to microorganisms present in the soil. Additionally, while mechanical wounding of the alfalfa roots induced ATI mRNA synthesis both in the
roots and in the leaves, microbial infection of the roots triggered ATI mRNA synthesis in the roots but not in the leaves. These results suggest that both local and systemic signalling pathways for proteinase inhibitor synthesis are present in alfalfa plants.
Molecular cloning of cDNAs for auxin-induced mRNAs and developmental
expression of the auxin-inducible genes.
Author: Reddy AS, Jena PK, Mukherjee S K, Poovaiah BW.
Department of Horticulture and Landscape Architecture, Washington State University, Pullman 99164-6414.
differential hybridization, two auxin-inducible cDNA clones (lambda SAR1
and lambda SAR2) have been isolated from a cDNA library constructed to
poly(A)+ mRNA from auxin-treated strawberry receptacles. Both the clones
have been used as probes to study the expression of the auxin-induced
genes in pollinated and unpollinated fruits of various stages of
development and in different organs. A high level of auxin-induced mRNAs
is found in pollinated fruits as compared to unpollinated fruits of the
same age, suggesting that the expression of the auxin-induced genes is
developmentally regulated and the level of auxin-induced mRNAs is
regulated by endogenous auxin. Furthermore, our data on the expression of
lambda SAR1 and lambda SAR2 genes in pollinated and unpollinated fruits
revealed a positive correlation between growth of strawberry fruit and
the induction of mRNA corresponding to the lambda SAR1 and lambda SAR2
clones. Ethylene has no effect on the expression of the auxin-induced
mRNAs. lambda SAR1 mRNA is not detected in other parts of strawberry
plants whereas lambda SAR2 mRNA is present in roots. Furthermore, mRNA
corresponding to lambda SAR1 and lambda SAR2 is not detected in other
auxin-responsive plant systems such as pea epicotyls and bean explants.
PMID: 2102846 [PubMed - indexed for MEDLINE]
Marker-free Insect Resistant Transgenic Vegetables Using Agrobacterium
Authors: K. Azhakanandam, V.A. Ansingkar, P. Girhepuje, M. Narendran, S.K. Mukherjee, And U.B. Zehr
Mahyco Life Sciences Research Cenre Dawalwadi, PO Box 76, Jalna 431 203, Maharashtra, India.
Marker-free transformation systems have the advantages of introducing multiple agronomically important genes, and at the same time, avoiding the problem of introducing multiple copies of the selectable markers. Thus a system has been employed for the production of marker-free transgenic Tomato and Brinjal. Two different methods of Agrobacterium-mediated co-transformation were used: 1) a single Agrobacterium tumefaciens strain carrying two separate binary vectors [one vector carrying the nptII gene and the other vector carrying the cr1A(c) gene]; 2) two different Agrobacterium tumefaciens strains each carrying a separate binary vector. This system has already been validated by us for Rice. A reproducible transformation system has been established for the production of insect resistant transgenic Tomato and Brinjal, as a prerequisite for generating a large number of marker-free transgenic vegetables. The stable integration and the expression of the introduced cry1A(c), along with nptII marker gene in T0, T1 and T2 plants have been confirmed and characterized by PCR, Southern analysis, ELISA and Bioassay against a major pests, shoot and fruit borer of Brinjal (Leucinodes orbonalis) and fruit borer of Brinjal and Tomato (Helicoverpa armigera). The same system, with modification, has been employed to generate maker-free insect resistant vegetables.