The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species （TBARS） assay, total phenol...The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species （TBARS） assay, total phenol content, evaluation of reactive oxygen species （ROS） in liver mitochondria, Fe2＋ chelating and 2,2-diphenyl-lpicrylhydrazyl （DPPH） scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE＋ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested （15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous）. Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2＋ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.展开更多
Tomato has emerged as an emblematic model plants for fleshy fruit research and tomato fruit ripening is a complex and highly coordinated developmental process.The many physiology and biochemical processes associated w...Tomato has emerged as an emblematic model plants for fleshy fruit research and tomato fruit ripening is a complex and highly coordinated developmental process.The many physiology and biochemical processes associated with tomato fruit ripening require changes in the expression of hundreds to thousands of genes.Gene expression is regulated by transcriptional and post-transcriptional pathways,one of the recently discovered mechanisms in plants was small RNAs mediated gene silencing at post-transcriptional(PTGS) level.Intriguingly,several mi RNAs and endogenous si RNAs were revealed to be involved in the fruit ripening process which opened a new avenue in the field of fleshy fruit biology.This review compiled the most recent advances made in deciphering the regulation functions of mi RNAs and si RNAs in tomato fruit ripening.It also emphasized the new perspectives now possible in the small RNAs regulation research in tomato fruit ripening and senescence.展开更多
The study describes the scope of clonal propagation of guava (Psidium guajava Linn.) by stem cutting collected from mature stockplants. Cuttings were treated with 0, 0.2%, 0.4% and 0.8% IBA solution and rooted in the ...The study describes the scope of clonal propagation of guava (Psidium guajava Linn.) by stem cutting collected from mature stockplants. Cuttings were treated with 0, 0.2%, 0.4% and 0.8% IBA solution and rooted in the non-mist propagator. Rooted cuttings were allowed to grow in the polybags filled with soil and cow-dung mixed in the ratio of 3: 1 (by volume) for three months to assess the steckling capacity and initial growth performance. The study reveals that the species is amenable for clonal propagation by mature stem cutting. The highest rooting percentage (60%) was observed in the cuttings treated with 0.4% IBA solution followed by 0.2% IBA and the lowest was in controlled cuttings. The maximum number of primary root (32.7) was developed in the cuttings treated with 0.8% IBA solution followed by 0.4% IBA and the lowest was in the cuttings without IBA treatment. The highest survival percentage (70.9) was observed in the cuttings rooted with 0.4% IBA treatment and the lowest (58.3) was in the cuttings without any treatment. However, there was no significant variation in height growth of cutlings due to IBA treatments in rooting.展开更多
Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening p...Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening process. With antisense ACS tomato, Nr mutant tomato and cultivated tomato as materials, Northern blot hybridization showed that PG, LeEXP1 and LOXexpressed differently in different parts of cultivated tomato fruit during ripening, which was related to fruit ripening. The ripening process of columella and radial pericarp was faster than pericarp. In both Nr mutant and antisense ACS transgenic tomato fruit, expression levels ofPG, LeEXPI and LOXwere generally lower than those in cultivated fruit but still related to fruit ripening. The expression levels ofPG, LeEXP1 and LOX increased in the mature green tomato fruits after 0.5 h treatment with ethylene （100 μL/L）. These results indicate that gene expression ofPG, LeEXP1 and LOXwere positively regulated by ethylene. The time and cumulative effect of the concentration exists in the expression of PG regulated by ethylene. The regulation of LOX expression mainly depended on the fruit development after great amount of ethylene was produced. PG played a major role in ripening and softening of tomato fruit, and cooperated with the regulation of EXP and LOX.展开更多
文摘The antioxidant activities of the ethyl acetate fraction and aqueous extract of unripe fruit of Carica papaya were compared and investigated in vitro using thiobarbituric reactive species （TBARS） assay, total phenol content, evaluation of reactive oxygen species （ROS） in liver mitochondria, Fe2＋ chelating and 2,2-diphenyl-lpicrylhydrazyl （DPPH） scavenging activities. Both extracts had high antioxidant properties and could inhibit FeE＋ and sodium nitroprusside lipid peroxidation in the liver. Total phenol content of ethyl acetate fraction and aqueous extract were 4.50 ±2.26 and 1.21±3.12 mg/g, respectively. Both extracts had a maximal effect at the lowest concentrations tested （15 μg/mL for ethyl acetate and 150 μg/mL for the aqueous）. Ethyl acetate fraction showed that the highest values of antioxidant activity is probably associated with its high phenolic content, Fe2＋ chelating and DPPH scavenging activities. It is therefore concluded that ethyl acetate fraction and to a less extent the aqueous fractions are potent inhibitor of lipid peroxidation.
基金Supported by the National Natural Sciences Foundation of China(31401536)the Natural Science Foundation of Beijing(6144020)+1 种基金the Special Fund of China Agriculture Research System(CARS-25)the Special Fund for Agro-scientific Research in the Public Interest(201203095)
文摘Tomato has emerged as an emblematic model plants for fleshy fruit research and tomato fruit ripening is a complex and highly coordinated developmental process.The many physiology and biochemical processes associated with tomato fruit ripening require changes in the expression of hundreds to thousands of genes.Gene expression is regulated by transcriptional and post-transcriptional pathways,one of the recently discovered mechanisms in plants was small RNAs mediated gene silencing at post-transcriptional(PTGS) level.Intriguingly,several mi RNAs and endogenous si RNAs were revealed to be involved in the fruit ripening process which opened a new avenue in the field of fleshy fruit biology.This review compiled the most recent advances made in deciphering the regulation functions of mi RNAs and si RNAs in tomato fruit ripening.It also emphasized the new perspectives now possible in the small RNAs regulation research in tomato fruit ripening and senescence.
文摘The study describes the scope of clonal propagation of guava (Psidium guajava Linn.) by stem cutting collected from mature stockplants. Cuttings were treated with 0, 0.2%, 0.4% and 0.8% IBA solution and rooted in the non-mist propagator. Rooted cuttings were allowed to grow in the polybags filled with soil and cow-dung mixed in the ratio of 3: 1 (by volume) for three months to assess the steckling capacity and initial growth performance. The study reveals that the species is amenable for clonal propagation by mature stem cutting. The highest rooting percentage (60%) was observed in the cuttings treated with 0.4% IBA solution followed by 0.2% IBA and the lowest was in controlled cuttings. The maximum number of primary root (32.7) was developed in the cuttings treated with 0.8% IBA solution followed by 0.4% IBA and the lowest was in the cuttings without IBA treatment. The highest survival percentage (70.9) was observed in the cuttings rooted with 0.4% IBA treatment and the lowest (58.3) was in the cuttings without any treatment. However, there was no significant variation in height growth of cutlings due to IBA treatments in rooting.
基金Supported by National Project of Scientific and Technical Supporting Programs Funded by Ministry of Science and Technology of China (No.2006BAD22B01)National Natural Science Foundation of China (No.30800767)Postdoctoral Fund of China (No.20080430725)
文摘Fruit ripening is a complex process and is regulated by many factors. Ethylene and polygalacturonase （PG）, lipoxygenase （LOX）, expansin （EXP） are all critical regulating factors in fruit ripening and softening process. With antisense ACS tomato, Nr mutant tomato and cultivated tomato as materials, Northern blot hybridization showed that PG, LeEXP1 and LOXexpressed differently in different parts of cultivated tomato fruit during ripening, which was related to fruit ripening. The ripening process of columella and radial pericarp was faster than pericarp. In both Nr mutant and antisense ACS transgenic tomato fruit, expression levels ofPG, LeEXPI and LOXwere generally lower than those in cultivated fruit but still related to fruit ripening. The expression levels ofPG, LeEXP1 and LOX increased in the mature green tomato fruits after 0.5 h treatment with ethylene （100 μL/L）. These results indicate that gene expression ofPG, LeEXP1 and LOXwere positively regulated by ethylene. The time and cumulative effect of the concentration exists in the expression of PG regulated by ethylene. The regulation of LOX expression mainly depended on the fruit development after great amount of ethylene was produced. PG played a major role in ripening and softening of tomato fruit, and cooperated with the regulation of EXP and LOX.
