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Authors
Info
R.A. Wilson1,2*,
S. Gupta1,
M.K. Sangha1,2
and G. Kaur1Â
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1Department of
Plant Breeding and Genetics, Punjab Agricultural University,
Ludhiana-141 004, India
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2Department of
Biochemistry, Punjab Agricultural University, Ludhiana-141 004, IndiaÂ
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*Corresponding Author Email :
bobzrobin@gmail.com
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Abstract
Aim: Heat stress due to
increase in global temperature is posing a serious threat to the agricultural
sector in many parts of the world. The present investigation was, therefore,
undertaken to study the mechanism of thermos-tolerance in four-day-old
seedlings of Brassica rapa (44 genotypes) on the basis of various
enzymatic and non-enzymatic antioxidants. The information gathered through
the present investigation can pave way for imparting tolerance to Brassica
genotypes by altering enzyme activities through genetic engineering
interventions. Â
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Methodology: A total of 44
genotypes were evaluated for survival percentage, electrolyte leakage and
chlorophyll content under heat stress conditions. Seedlings were
characterized by membrane lipid peroxidation and antioxidants viz. peroxidase
and catalase activities, proline and glutathione. Heat stress conditions were
created by exposing four-day-old seedlings to 45ºC for 4.5 hr. Out of 44
genotypes, four genotypes (JMT-04-03, TL-2035, TL-98-01 and PBT-37) were
thermos-tolerant. Tolerant genotypes registered survival greater than 65%,
moderately tolerant between 35-65% and susceptible less than 35%. Â Â Â Â Â
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Results: Among various
parameters studied, under heat stress, a significant increase in electrolyte
leakage, lipid peroxidation, peroxidase activity, glutathione and proline
content was observed in comparison to control seedlings, whereas a decline in
CAT activity and chlorophyll content was recorded.Â
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Interpretation: Biochemical
changes observed in the activities and contents of various parameters studied
could be linked with enhanced tolerance to heat stress damage in Brassica
rapa which could further be used as a marker for screening against heat
stress.
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Key
words:
Antioxidants, Brassica rapa, Heat stress,
Lipid Peroxidation, Reactive oxygen species
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