共查询到20条相似文献,搜索用时 31 毫秒
1.
Manvir Kaur Anil Kumar Gupta Vikramjit Kaur Zhawar 《Journal of plant biochemistry and biotechnology.》2014,23(1):18-30
Two wheat (Triticum aestivum) cultivars, C306 (drought tolerant) and PBW343 (drought susceptible) were compared for their response to exogenous ABA, water stress (WS) and combined (ABA plus WS) during their seedlings growth. Their responses were studied in the form of seedlings growth, antioxidant potential of roots and shoots and expression levels of LEA genes in shoots. ABA treatment led to increase in levels of ascorbate, ascorbate to dehydroascorbate ratio, antioxidant enzymes and decreases in levels of dehydroascorbate, malondialdehyde (MDA). Decrease in biomass, ascorbate contents, ascorbate to dehydroascorbate ratios and antioxidant enzymes was more in PBW343 than in C306 under WS. Dehydroascorbate and MDA levels were higher in PBW343 than in C306 under WS. ABA plus WS improved some of these features from their levels under WS in PBW343. Proline contents were not increased significantly under ABA in both cultivars. Out of ten LEA genes studied, six LEA genes were induced more under WS than under ABA in C306 but equally induced in PBW343. Four LEA genes were induced earlier in PBW343 but later in C306. Wdhn13 was induced more under ABA than under WS in C306 while it was non-responsive to both stresses in PBW343. 相似文献
2.
Effects of putrescine (Put) on responses of wheat (Triticum aestivum) seedlings or detached tillers at mid-milky stage to high temperature (HT) stress were investigated. The heat tolerant cv. PBW 343 exhibited higher content of antioxidants and activities of antioxidative enzymes, while lower content of lipid peroxides as compared to the heat-sensitive cv. HD 2329. HT elevated peroxidase (POX) and superoxide dismutase (SOD) activities, while diamine oxidase (DAO) and polyamine oxidase (PAO) activities were reduced in roots, shoots and developing grains. Application of Put under HT further enhanced POX and SOD activities along with increased content of ascorbate and tocophereol in grains. Invariably POX and SOD revealed higher activities in roots while CAT, DAO and PAO activities were higher in shoots. The content of lipid peroxides was increased in roots and shoots of HT stressed seedlings but less in Put-treated cv. PBW 343. 相似文献
3.
Effect of sodium nitroprusside (SNP), a donor of nitric oxide (NO) was examined in two wheat (Triticum aestivum L.) cultivars, C 306 (heat tolerant) and PBW 550 (comparatively heat susceptible) to study the extent of oxidative injury and activities of antioxidant enzyme in relation to high temperature (HT) stress. HT stress resulted in a marked decrease in membrane thermostability (MTS) and 2, 3, 5-triphenyl tetrazolium chloride (TTC) cell viability whereas content of lipid peroxide increased in both the cultivars. The tolerant cultivar C 306 registered less damage to cellular membranes compared to PBW 550 under HT stress. Activities of antioxidant enzymes viz, superoxide dismutase, catalase, ascorbate peroxidase, guaicol peroxidase and glutathione reductase increased with HT in both the cultivars. Following treatment with SNP, activities of all antioxidant enzymes further increased in correspondence with an increase in MTS and TTC. Apparently, lipid peroxide content was reduced by SNP more in shoots of heat tolerant cultivar C 306 indicating better protection over roots under HT stress. The up-regulation of the antioxidant system by NO possibly contributed to better tolerance against HT induced oxidative damage in wheat. 相似文献
4.
F. J. Xu G. Li C. W. Jin W. J. Liu S. S. Zhang Y. S. Zhang X. Y. Lin 《Biologia Plantarum》2012,56(1):89-96
The present study investigated the effects of aluminum on lipid peroxidation, accumulation of reactive oxygen species and
antioxidative defense systems in root tips of wheat (Triticum aestivum L.) seedlings. Exposure to 30 μM Al increased contents of malondialdehyde, H2O2, suproxide radical and Evans blue uptake in both genotypes, with increases being greater in Al-sensitive genotype Yangmai-5
than in Al-tolerant genotype Jian-864. In addition, Al treatment increased the activity of superoxide dismutase (SOD), peroxidase
(POD), catalase (CAT), ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), glutathione reductase (GR) and
glutathione peroxidase (GPX), as well as the contents of ascorbate (AsA) and glutathione (GSH) in both genotypes. The increased
activities SOD and POD were greater in Yangmai-5 than in Jian-864, whereas the opposite was true for the activities of CAT,
APX, MDHAR, GR and GPX and the contents of AsA and GSH. Consequently, the antioxidant capacity in terms of 2,2-diphenyl-1-picrylhydrazyl
(DPPH)-radical scavenging activity and ferric reducing/antioxidant power (FRAP) was greater in Jian-864 than in Yangmai-5. 相似文献
5.
Content of polyamines and activities of antioxidative enzymes in response to stripe rust disease caused by Puccinia striiformis have been studied in two wheat (Triticum aestivum L.) cultivars PBW 343 (resistant) and HD 2329 (susceptible). Various infection stages ranging from traces to 100 % were collected.
Infection leads to stimulation of peroxidase (POD), superoxide dismutase (SOD), catalase, diamine oxidase and polyamine oxidase
activities along with increase in putrescine, spermidine and spermine content while ascorbate, tocopherol and chlorophyll
content decreased in HD 2329 and no visible symptoms appeared in PBW 343. Histochemical localization pattern of POD and SOD
activities revealed correlation with lignin deposition in cell walls. 相似文献
6.
Effects of exogenous salicylic acid (SA) on plant growth, contents of Na, K, Ca and Mg, activities of superoxide dismutase
(SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX), dehydroascorbate reductase (DHAR), glutathione reductase (GR)
and catalase (CAT), and contents of ascorbate and glutathione were investigated in tomato (Lycopersicon esculentum L.) plants treated with 100 mM NaCl. NaCl treatment significantly increased H2O2 content and lipid peroxidation indicated by accumulation of thiobarbituric acid reactive substances (TBARS). A foliar spray
of 1 mM SA significantly decreased lipid peroxidation caused by NaCl and improved the plant growth. This alleviation of NaCl
toxicity by SA was related to decreases in Na contents, increases in K and Mg contents in shoots and roots, and increases
in the activities of SOD, CAT, GPX and DHAR and the contents of ascorbate and glutathione. 相似文献
7.
Increased Antioxidant Activity under Elevated Temperatures: A Mechanism of Heat Stress Tolerance in Wheat Genotypes 总被引:4,自引:0,他引:4
An experiment was conducted with three wheat (Triticum aestivum L.) genotypes C 306, HD 2285 and HD 2329 (differently susceptible to water and temperature stress) to study the extent of oxidative injury and activities of antioxidant enzymes in relation to heat stress induced by manipulating dates of sowing. Increase in temperature by late sowing significantly decreased leaf relative water content (RWC), ascorbic acid content, and increased H2O2 content and lipid peroxidation in all the genotypes at 8 and 23 d after anthesis. Temperature tolerant genotypes C 306, closely followed by HD 2285 were superior to HD 2329 in maintaining high RWC, ascorbic acid content, and lower H2O2 content and lipid peroxidation (malondialdehyde content) under high temperature (late sowing) at the two stages. Activities of superoxide dismutase and catalase were highest in HD 2285 followed by C 306 and minimum in HD 2329 while ascorbate peroxidase activity was highest in C 306. 相似文献
8.
Effect of salicylic and abscisic acid administered through detached tillers on antioxidant system in developing wheat grains under heat stress 总被引:1,自引:0,他引:1
The mechanism imparting thermotolerance by salicylic acid (SA) and abscisic acid (ABA) is still unresolved using either spraying
technique or in vitro conditions. Alternative way of studying these effects under near in vivo conditions is through the use
of liquid culturing technique. Effects of SA and ABA (100 μM) on antioxidative enzymes, antioxidants and lipid peroxidation
were studied in detached tillers of three wheat (Triticum aestivum L.) cultivars PBW 343, C 306 (heat tolerant) and WH 542 (heat susceptible) cultured in a liquid medium. Ears were subjected
to heat shock treatment (45°C for 2 h) and then maintained at 25°C for 5 days. Heat shock treatment resulted in increased
peroxidase (POD) activity, while superoxide dismutase (SOD) and catalase (CAT) activities were reduced compared to control.
The decrease in CAT activity was more significant in susceptible cultivar WH 542. Concomitantly, content of α-tocopherol and
lipid peroxides increased in heat-treated wheat ears, whereas contents of total ascorbate level were reduced. Following treatment
with SA and ABA, activities of all three antioxidative enzymes increased in correspondence with an increase in ascorbate and
α-tocopherol content. Apparently, lipid peroxide content was reduced by SA in heat tolerant cultivars (PBW 343 and C 306)
whereas in susceptible cultivar it was decreased by ABA. The up-regulation of the antioxidant system by SA and ABA possibly
contributes to better tolerance against heat shock-induced oxidative damage in wheat grains. 相似文献
9.
10.
Peroxisomal APX knockdown triggers antioxidant mechanisms favourable for coping with high photorespiratory H2O2 induced by CAT deficiency in rice 下载免费PDF全文
RACHEL H. V. SOUSA FABRICIO E. L. CARVALHO CAROL W. RIBEIRO GISELE PASSAIA JULIANA R. CUNHA YUGO LIMA‐MELO MÁRCIA MARGIS‐PINHEIRO JOAQUIM A. G. SILVEIRA 《Plant, cell & environment》2015,38(3):499-513
The physiological role of peroxisomal ascorbate peroxidases (pAPX) is unknown; therefore, we utilized pAPX4 knockdown rice and catalase (CAT) inhibition to assess its role in CAT compensation under high photorespiration. pAPX4 knockdown induced co‐suppression in the expression of pAPX3. The rice mutants exhibited metabolic changes such as lower CAT and glycolate oxidase (GO) activities and reduced glyoxylate content; however, APX activity was not altered. CAT inhibition triggered different changes in the expression of CAT, APX and glutathione peroxidase (GPX) isoforms between non‐transformed (NT) and silenced plants. These responses were associated with alterations in APX, GPX and GO activities, suggesting redox homeostasis differences. The glutathione oxidation‐reduction states were modulated differently in mutants, and the ascorbate redox state was greatly affected in both genotypes. The pAPX suffered less oxidative stress and photosystem II (PSII) damage and displayed higher photosynthesis than the NT plants. The improved acclimation exhibited by the pAPX plants was indicated by lower H2O2 accumulation, which was associated with lower GO activity and glyoxylate content. The suppression of both pAPXs and/or its downstream metabolic and molecular effects may trigger favourable antioxidant and compensatory mechanisms to cope with CAT deficiency. This physiological acclimation may involve signalling by peroxisomal H2O2, which minimized the photorespiration. 相似文献
11.
Spermidine pretreatment enhances heat tolerance in rice seedlings through modulating antioxidative and glyoxalase systems 总被引:2,自引:0,他引:2
This study was undertaken to investigate the possible involvement of the antioxidant defense and glyoxalase systems in protecting rice seedlings from heat-induced damage in the presence of spermidine (Spd). Hydroponically grown 14-day-old seedlings were subjected to foliar spray with Spd (1 mM, 24 h) prior to heat stress (42 °C, 48 h) followed by subsequent recovery (27 °C, 48 h). Lipoxygenase activity, malondialdehyde (MDA), hydrogen peroxide (H2O2) and proline (Pro) content increased significantly whereas fresh weight (FW) and chlorophyll (Chl) content decreased during heat stress and after recovery, indicating unrecoverable damage to rice seedlings. Heat-induced damage was also evident in decreased levels of ascorbate (AsA), glutathione (GSH), and AsA and GSH redox ratios. Superoxide dismutase (SOD) and catalase (CAT) activities increased during heat stress but declined after recovery. Activities of glutathione peroxidase (GPX), ascorbate peroxidase (APX), monodehydroascorbate reductase, dehydroascorbate reductase (DHAR) and glutathione reductase (GR) decreased during heat stress but an opposite trend for most of these enzymes was observed after recovery. Heat stress also resulted in significant increases in the activities of glyoxalase enzymes (Gly I and Gly II). In contrast, exogenous Spd protected rice seedlings from heat-induced damage as marked by lower levels of MDA, H2O2, and Pro content coupled with increased levels of AsA, GSH, FW, Chl, and AsA and GSH redox status. After recovery, Spd-pretreated heat-exposed seedlings displayed higher activities of SOD, CAT, GPX, GST APX, DHAR and GR as well as of Gly I and Gly II. In addition, polyamine analysis revealed that exogenously applied Spd significantly elevated the levels of free and soluble conjugated Spd. Therefore, we conclude from our results that heat exposure provoked an oxidative burden while enhancement of the antioxidative and glyoxalase systems by Spd rendered rice seedlings more tolerant to heat stress. Further, co-induction of the antioxidative and glyoxalase systems was closely associated with Spd mediated enhanced level of GSH. 相似文献
12.
Chokri Hafsi María C. Romero-Puertas Luis A. del Río Chedly Abdelly Luisa M. Sandalio 《Acta Physiologiae Plantarum》2011,33(1):193-202
The objective of the present study was to determine the influence of potassium deprivation on the halophyte species Hordeum maritimum grown in hydroponics for 2 weeks. Treatments were with potassium (+K) or without potassium (−K). Growth, water status, mineral
nutrition, parameters of oxidative stress [malondialdehyde (MDA), carbonyl groups (C=O), and hydrogen peroxide concentration
(H2O2) contents], antioxidant enzyme activities [superoxide dismutase (SOD, EC 1.15.1.1), catalase (CAT, EC 1.11.1.6), guaiacol
peroxidase (GPX, EC 1.11.1.7), ascorbate peroxidase (APX, EC 1.11.1.11), monodehydroascorbate peroxidase (MDHAR, EC 1.6.5.4),
dehydroascorbate peroxidase (DHAR, EC 1.8.5.1), and glutathione reductase (GR, EC 1.6.4.2)], and antioxidant molecules [ascorbate
(ASC), and glutathione (GSH)] were determined. Results showed that the growth of vegetative organs decreased owing to potassium
deficiency with roots (−36%) more affected than shoots (−12%). Water status was only diminished in roots (reduction of 24%).
Potassium deprivation decreased potassium concentration in both organs, this decrease was more pronounced in roots (−81%)
than in shoots (−55%). In contrast to carbonyl groups, MDA content increased owing to potassium deprivation. Except for CAT
activity that remained unaffected; SOD, GPX, APX, GR, MDHAR, and DHAR activities were significantly increased. H2O2 concentration was negatively correlated with the activities of enzymes and the accumulation of non-enzymatic antioxidants
implicated in its detoxification. In conclusion, a cooperative process between the antioxidant systems is important for the
tolerance of H. maritimum to potassium deficiency. 相似文献
13.
Seedlings of rice (Oryza sativa L.) cv. Pant-12 grown in sand cultures containing 200 and 400 μM NiSO4, showed a decrease in length and fresh weight of roots and shoots. Nickel was readily taken up by rice seedlings and the
concentration was higher in roots than shoots. Nickel-treated seedlings showed increased rates of superoxide anion (O2
•−
) production, elevated levels of H2O2 and thiobarbituric acid reactive substances (TBARS) demonstrating enhanced lipid peroxidation, and a decline in protein thiol
levels indicative of increased protein oxidation compared to controls. With progressively higher Ni concentrations, non-protein
thiol and ascorbate (AsA) increased, whereas the level of low-molecular-weight thiols (such as glutathione and hydroxyl-methyl
glutathione), the ratio of these thiols to their corresponding disulphides, and the ratio of AsA to dehydroascorbic acid declined
in the seedlings. Among the antioxidant enzymes studied, the activities of all isoforms of superoxide dismutase (Cu-Zn SOD,
Mn SOD and Fe SOD), guaiacol peroxidases (GPX) and ascorbate peroxidase (APX) increased in Ni-treated seedlings, while no
clear alteration in catalase activity was evident. Activity of the ascorbate-glutathione cycle enzymes monodehydroascorbate
reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR)—significantly increased in Ni-treated
seedlings. However such increase was apparently insufficient to maintain the intracellular redox balance. Results suggest
that Ni induces oxidative stress in rice plants, resulting in enhanced lipid peroxidation and decline in protein thiol levels,
and that (hydroxyl-methyl) glutathione and AsA in conjunction with Cu-Zn SOD, GPX and APX are involved in stress response. 相似文献
14.
Abstract Isoproturon at the recommended field dose (RFD) significantly reduced fresh and dry weights of shoots and roots as well as chlorophyll and carotenoid contents of 10-day-old maize seedlings during the following 20 days. The higher the herbicide dose, the greater the reduction. Meanwhile, ascorbate (AsA) and reduced glutathione (GSH) increased in leaves for only the first few days. Similar increases in activities of superoxide dismutase (SOD), catalase (CAT), guaiacol peroxidase (GPX) and ascorbate peroxidase (APX) were detected. Low doses caused general increases while high doses induced diminutions; however, CAT and APX activities were inhibited by all doses. Nevertheless, H2O2 was significantly accumulated throughout the experiment; the magnitude of accumulation increased with time and herbicide dose. On the contrary, there were significant inhibitions in activities of the glutathione S-transferase (GST) isoforms (GST(CDNB), GST(ALA), or GST(MET)) with no variation in GST(ATR); the inhibition was greater with increasing isoproturon doses. These findings suggest the occurrence of an oxidative stress induced by isoproturon, a state that prolonged with increasing herbicide dose and/or treatment time. Moreover, V max of GST was lowered by isoproturon, whereas K m was unchanged, indicating that the herbicide is a competitive inhibitor of GST. 相似文献
15.
Wheat (Triticum aestivum L. cv. ‘Zyta’) seedlings were treated with 10, 100 and 200 μM Ni. Tissue Ni accumulation, length, relative water content
(RWC), proline and H2O2 concentrations as well as the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol
peroxidase (POD) and glutathione S-transferase (GST) were studied in the shoots and roots after 6 days of Ni exposure. Treatment
with Ni, except for its lowest concentration, resulted in a significant reduction in wheat growth. In comparison to the shoots,
the roots showed greater inhibition of elongation, which corresponded with higher accumulation of Ni in these organs. Both
shoots and roots responded to Ni application with a decrease in RWC and enhancement in proline concentration. Greater dehydration
of the shoot tissue was accompanied by more intense accumulation of proline. Treatment of the wheat seedlings with the highest
concentration of Ni led to about 60% increase in H2O2 concentration in both studied organs. Apart from CAT, constitutive activities of antioxidative enzymes were much higher in
the roots than in the shoots. Exposure of the seedlings to Ni resulted in SOD activity decline, which was more marked in the
roots. While the shoots showed a substantial decrease (up to 30%) in CAT activity, in the roots the activity of this enzyme
remained unchanged. After Ni application APX, POD and GST activities increased several-fold in the shoots, whereas in the
roots they were not significantly altered. The results suggest that differential antioxidative responses of the shoots and
roots of wheat seedlings to Ni stress might be related to diverse constitutive levels of antioxidant enzyme activities in
both organs. 相似文献
16.
We tested the mode of action of Cd on photosynthesis and activities of ATP-sulfurylase (ATP-S), catalase (CAT), superoxide
dismutase (SOD), ascorbate peroxidase (APX), glutathione reductase (GR), and on contents of phytochelatins (PCs) and glutathione
(GSH) in two cultivars of wheat (Triticum aestivum L.) PBW-343 and WH-542 differing in yield potential. Cd treatment increased Cd content and photosynthetic activity in PBW-343
more than in WH-542. The activities of APX, GR, ATP-S, and synthesis of PCs and GSH were also increased by Cd, but the CAT
and SOD activities were inhibited in both the cultivars. The efficient functioning of antioxidative enzymes, production of
PCs and GSH, helped in counteracting the effects of Cd namely in PBW-343, protected photosynthetic ability, and increased
the tolerance to Cd. 相似文献
17.
Nitric oxide modulates antioxidant defense and the methylglyoxal detoxification system and reduces salinity-induced damage of wheat seedlings 总被引:2,自引:0,他引:2
Mirza Hasanuzzaman Mohammad Anwar Hossain Masayuki Fujita 《Plant biotechnology reports》2011,5(4):353-365
The present study investigates the possible regulatory role of exogenous nitric oxide (NO) in antioxidant defense and methylglyoxal
(MG) detoxification systems of wheat seedlings exposed to salt stress (150 and 300 mM NaCl, 4 days). Seedlings were pre-treated
for 24 h with 1 mM sodium nitroprusside, a NO donor, and then subjected to salt stress. The ascorbate (AsA) content decreased
significantly with increased salt stress. The amount of reduced glutathione (GSH) and glutathione disulfide (GSSG) and the
GSH/GSSG ratio increased with an increase in the level of salt stress. The glutathione S-transferase (GST) activity increased significantly with severe salt stress (300 mM). The ascorbate peroxidase (APX), monodehydroascorbate
reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT) and glutathione peroxidase (GPX) activities did not show
significant changes in response to salt stress. The glutathione reductase (GR), glyoxalase I (Gly I), and glyoxalase II (Gly
II) activities decreased upon the imposition of salt stress, especially at 300 mM NaCl, with a concomitant increase in the
H2O2 and lipid peroxidation levels. Exogenous NO pre-treatment of the seedlings had little influence on the non-enzymatic and
enzymatic components compared to the seedlings of the untreated control. Further investigation revealed that NO pre-treatment
had a synergistic effect; that is, the pre-treatment increased the AsA and GSH content and the GSH/GSSG ratio, as well as
the activities of MDHAR, DHAR, GR, GST, GPX, Gly I, and Gly II in most of the seedlings subjected to salt stress. These results
suggest that the exogenous application of NO rendered the plants more tolerant to salinity-induced oxidative damage by enhancing
their antioxidant defense and MG detoxification systems. 相似文献
18.
The effects of foliar spraying with spermidine (Spd) on antioxidant system in tomato (Lycopersicon esculentum Mill.) seedlings were investigated under high temperature stress. The high temperature stress significantly inhibited plant growth and reduced chlorophyll (Chl) content. Application of exogenous 1 mM Spd alleviated the inhibition of growth induced by the high temperature stress. Malondialdehyde (MDA), hydrogen peroxide (H2O2) content and superoxide anion (O2) generation rate were significantly increased by the high temperature stress, but Spd significantly reduced the accumulation of reactive oxygen species (ROS) and MDA content under the stress. The high temperature stress significantly decreased glutathione (GSH) content and activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR), but increased contents of dehydroascorbic acid (DHA), ascorbic acid (AsA), and oxidized glutathione (GSSG) in tomato leaves. However, Spd significantly increased the activities of antioxidant enzymes, levels of antioxidants and endogenous polyamines in tomato leaves under the high temperature stress. In addition, to varying degrees, Spd regulated expression of MnSOD, POD, APX2, APX6, GR, MDHAR, DHAR1, and DHAR2 genes in tomato leaves exposed to the high temperature stress. These results suggest that Spd could change endogenous polyamine levels and alleviate the damage by oxidative stress enhancing the non-enzymatic and enzymatic antioxidant system and the related gene expression. 相似文献
19.
The purpose of this work was to evaluate the effect of 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP) on the activity
of antioxidative system and lipid peroxidation in the leaves of reed canary grass (Phalaris arudinacea). The activity of catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), glutathione reductase (GR) and glutathione
S-transferase (GST) as well as the content of glutathione, ascorbate and phenolic compounds were determined. An induced-increase
in the APX, CAT, GPX and GR activities was stronger for PCP, while a significant increase in the GST activity was noted only
for 2,4-DCP. Both compounds increased the content of phenolic compounds, oxidized and reduced glutathione as well as the content
of ascorbic acid. PCP induced stronger increase in lipid peroxidation than 2,4-DCP. The observed changes revealed that chlorophenols
induce oxidative stress and oxidative damage in the leaves of reed canary grass. 相似文献
20.
The regulation of contents and activities of peroxidase (POX), diamine oxidase (DAO) and polyamine oxidase (PAO) were determined
in relation to polyamines and lignin content in wheat (Triticum aestivum L.) grains. Two cultivars WH 542 (heat susceptible) and PBW 343 (heat tolerant) were used. Activities of POX, DAO and PAO
were substantially higher in PBW 343 as compared with WH 542 and appeared to be independently regulated. POX and PAO showed
peak activities at mid-milky stage (15 d post anthesis) while the activity of DAO showed continuous decline. Histochemical
localization of POX and PAO in situ revealed their presence in the chalazal cell walls, crease and seed coat. Substantially higher activities of enzymes in PBW
343 correlated well with a higher degree of lignification in the chalazal cells as compared to WH 542. 相似文献