Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.5.4 (SOR)
 720 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The glutathione-ascorbate (GSH-ASC) cycle in plants plays an important role in detoxifying reactive oxygen species. Little is known about how the enzymes and antioxidants in the maize GSH-ASC cycle respond to stress. We clarified the genome positions, exon-intron structures and predicted subcellular locations of the ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) families in maize. ABA treatment increased the transcript levels of most of the APX genes except ZmAPX3 and ZmAPX6, upregulated the transcription of ZmMDAR1 and downregulated the transcriptions of ZmMDAR3 and ZmMDAR4. However, it had little effect on the expressions of the ZmDHAR and ZmGR gene families. ABA treatment increased the activities of only 2 enzymes, ZmAPX and ZmDHAR. The PEG treatment led to similar expression patterns as that of ABA. ZmAPX1.1 and ZmAPX2 exhibited the same expression patterns under PEG treatment conditions. Enzyme activities were not affected by the PEG treatment with the exception of a significant decrease in MDAR activity that was observed after 6h. Compared to the ABA and PEG treatments, the NaCl treatment only slightly affected the transcription of the four gene families but significantly increased the activity of ZmGR. The ABA and PEG treatments elevate the ASC levels and decrease the GSSG level. Our results show that the gene families of the maize GSH-ASC redox cycle respond differently to abiotic stresses and suggest that APX and MDAR may play more important roles in stress tolerance in plants.
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PMID:Gene families of maize glutathione-ascorbate redox cycle respond differently to abiotic stresses. 2207 Sep 75

ABA regulation of antioxidant activity during post-germination desiccation and subsequent rehydration was studied in two wheat cultivars PBW 644 (ABA-higher sensitive and drought tolerant) and PBW 343 (ABA-lesser sensitive and drought susceptible) where 1 d-germinated seeds were exposed to ABA/ PEG- 6000 for next 1 d, desiccated for 4 d and subsequently rehydrated for 4 d. Ascorbate, dehydrascorbate to ascorbate ratio, malondialdehyde (MDA), hydroxyl radicals, and activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), alcohol dehydrogenase (AlcDH) and aldehyde dehydrogenase (AldDH) were measured in seedlings just before desiccation (2 d old), desiccated (6 d old) and rehydrated (10 d old) stages. ROS/NO signaling was studied under CT and ABA supply by supplying ROS and NO scavengers. During desiccation, both cultivars showed increase of oxidative stress (dehydroascorbate to ascorbate ratio, MDA, hydroxyl radicals) and antioxidant activity in the form of ascorbate content and AldDH activity while other antioxidant enzymes were not increased. PBW 644 showed higher antioxidant activity thus produced less oxidative stress compared to PBW 343. During rehydration, activities of all antioxidant enzymes and levels of ROS (hydroxyl radicals) were increased in both cultivars and MDA was decreased in PBW 343. ABA supply improved desiccation as well as rehydration by improving all parameters of antioxidant activity tested in this study. PEG supply resembled to ABA-supply for its effects. ABA/PEG improvements were seen higher in PBW 644. ROS/NO-signalling was involved under CT as well as under ABA for increasing antioxidant activity during desiccation as well as rehydration in both cultivars.
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PMID:ABA regulation of antioxidant activity during post-germination desiccation and subsequent rehydration in wheat. 3025 77