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Indian Journal of Biochemistry and Biophysics (IJBB) >
IJBB Vol.47 [2010] >
IJBB Vol.47(4) [August 2010] >
| Title: | Polygalacturonase inhibitor protein from fruits of anthracnose resistant and susceptible varieties of Chilli (Capsicum annuum L) |
| Authors: | Shivashankar, S
Thimmareddy, C
Roy, Tapas K |
| Keywords: | Polygalacturonase inhibitor protein
Colletotrichum capsicii
Chilli
Capsicum annuum
Anthracnose resistant and susceptible |
| Issue Date: | Aug-2010 |
| Publisher: | CSIR |
| Abstract: | Chilli
fruit is highly susceptible to anthracnose infection at the stage of harvest
maturity, due to which the fruit yield in the leading commercial variety Byadgi
is severely affected. Field studies on screening of several varieties for
resistance to anthracnose have shown that a variety of chilli AR-4/99K is
resistant to anthracnose infection. In many crops, resistance to fungal attack
has been correlated with PGIP activity in developing fruits based on which
transgenic varieties have been developed with resistance to fungi. The present
study was carried out to determine whether anthracnose resistance in
AR-4/99K was due to the increased levels of PGIP alone and/ or due to
differences, if any, in the properties of PGIP. Hence, a comparative study of
the properties of polygalacturonase inhibitor protein (PGIP) isolated from
fruits of anthracnose resistant chilli var AR-4/99K and a susceptible variety
Byadgi was conducted with the objective of utilizing the information in genetic
transformation studies. Both the PGIPs from anthracnose resistant and
susceptible varieties of chilli exhibited similarities in the elution pattern
on Sephadex gel, DEAE cellulose, PAGE and SDS-PAGE. The two PGIPs were active
over a wide range of pH and temperature. Both PGIPs showed differential
inhibitory activity against polygalacturonase (PG) secreted by Colletotrichum
gleosporoides, C. capsici, C. lindemuthianum, Fusarium moniliforme and Sclerotium rolfsii. The
inhibitory activity of PGIP from both resistant and susceptible varieties was
the highest (82% and 76%, respectively) against the PG from Colletotrichum
capsici, a pathogen causing anthracnose rot of chilli, while the activity
was lower (1.27 to 12.3%) on the other fungal PGs. Although PGIP activity
decreased with fruit maturation in both the varieties, the resistant variety
maintained a higher activity at 45 days after flowering (DAF) as compared to
the susceptible variety which helped it to overcome the infection by
anthracnose as against the susceptible variety (Byadgi) in which PGIP activity
was drastically reduced at maturity. The molecular mass of PGIP as determined
by SDS-PAGE was found to be 37 kDa. N-terminal sequence analysis of the PGIP
showed the first six amino acid residues from N-terminal end were
Asp-Thr-His-Lys-Ser-Glu (DTHKSE), respectively. The similarities in properties
of the two PGIPs support the earlier findings that resistance of
AR-4/99K to anthracnose fungus is a result of its higher PGIP activity at
maturity. |
| Page(s): | 243-248 |
| ISSN: | 0975-0959 (Online); 0301-1208 (Print) |
| Source: | IJBB Vol.47(4) [August 2010]
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