DEVELOPMENT OF FUNCTIONAL MUTANTS, CLONING AND EXPRESSIONAL ANALYSIS OF RESISTANCE GENE ANALOGS (RGAs) AND TRANSCRIPTION FACTOR (TF) GENES IN FRENCH BEAN (Phaseolus vulgaris L.)
Loading...
Date
2016-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Horticultural Sciences, Bagalkot (COLLEGE OF HORTICULTURE, GKVK POST, BANGALURU)
Abstract
The present study was undertaken to create spectral variability and to develop
functional mutants using Ethyl Methyl Sulphonate (EMS) in the background of the cv.
Arka Anoop of french bean. The EMS at 0.25% was found to be the LD50. A set of 1500
plants in M1 and similar population in plant-to-row manner in M2 generation was studied
for spectral variability. A wide range of variability for both qualitative and quantitative
traits including pole type, thin, thick, dark green and pale green colour and variegated
leaved, pink flowered and curved pod mutants in varying frequencies was recorded. A set
of ten mutant entries from each mutant category constituting 100 mutant lines was
evaluated in M3 generation. Cloning and sequence analysis of 95 RGA clones revealed
85% - 99% similarity to known R genes and recorded P-Loop (13 clones), kinase (4
clones) and TIR (4 clones) in the NBS-LLR domains that fell into six distinct
phylogenetic groups. The in silico genome wide identification of Transcription Factors
(TFs) lead to the identification of 58 TF families with maximum homology in french
bean. A set of 20 TF genes and 10 RGAs was tested for expression in manifesting the rust
and the MYMV diseases. Nine RGAs and AP2-2, AP2-3, AP2-4, AP2-5, B3-1, B3-2, B3-
3, BHLH-1, BHLH-2, BHLH-3, BHLH-4, BHLH-5, BZIP-1, BZIP-2 and BZIP-3 TFs
found upregulated in rust resistance. COHFBRGA-3, 4, 5 and 7, AP2-3, AP2-5, B3-2,
B3-3, BHLH-4, BZIP-1 and BZIP-2 genes down-regulated and COHFBRGA-2, 25, 27
and 38 genes of french bean were up-regulated in MYMV resistance manifestation
compared to control.