We have taken advantage of an acclimation phenomenon in a chilling-sensitive maize inbred to investigate the molecular, biochemical, and physiological responses to chilling in preemergent maize seedlings. Three-day-old seedlings were exposed to 4(deg)C for 7 days and did not survive chilling stress unless they were preexposed to 14(deg)C for 3 days. cDNAs representing three chilling acclimation-responsive (CAR) genes were isolated by subtraction hybridization and differential screening and found to be differentially expressed during acclimation. Identification of one of these CAR genes as cat3, which encodes the mitochondrial catalase3 isozyme, led us to hypothesize that chilling imposes oxidative stress in the seedlings. Hydrogen peroxide levels were elevated during both acclimation and chilling of nonacclimated seedlings. Further molecular and biochemical analyses indicated that whereas superoxide dismutase activity was not affected, the levels of cat3 transcripts and the activities of catalase3 and guaiacol peroxidase were elevated in mesocotyls during acclimation. Accumulation of H2O2 following a short treatment with aminotriazole, a catalase inhibitor, indicated that catalase3 seems to be an important H2O2-scavenging enzyme in the seedlings. Control 3-day-old seedlings pretreated with H2O2 or menadione, a superoxide-generating compound, at 27(deg)C induced chilling tolerance. Both of these chemical treatments also increased cat3 transcripts and catalase3 and guaiacol peroxidase activities. We suggest that peroxide has dual effects at low temperatures. During acclimation, its early accumulation signals the production of antioxidant enzymes such as catalase3 and guaiacol peroxidase. At 4(deg)C, in nonacclimated seedlings, it accumulates to damaging levels in the tissues due to low levels of these, and perhaps other, antioxidant enzymes.
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera