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The antioxidative defense system is involved in the premature senescence in transgenic tobacco (Nicotiana tabacum NC89).

Liu Y, Wang L, Liu H, Zhao R, Liu B, Fu Q, Zhang Y - Biol. Res. (2016)

Bottom Line: The levels of chlorophyll and soluble protein decreased and a lower seed biomass and reduced net photosynthetic rate (Pn) in transgenic plants.Combined with the expression analysis of senescence marker genes, these results indicate that senescence started in the leaves of the transgenic plants at the vegetative growth stage.The antioxidative defense system was compromised and the accumulation of reactive oxygen species (ROS) played an important role in the premature aging of transgenic plants.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, 61 Dai Zong Street, Tai'an, 271018, Shandong, People's Republic of China.

ABSTRACT

Background: α-Farnesene is a volatile sesquiterpene synthesized by the plant mevalonate (MVA) pathway through the action of α-farnesene synthase. The α-farnesene synthase 1 (MdAFS1) gene was isolated from apple peel (var. white winter pearmain), and transformed into tobacco (Nicotiana tabacum NC89). The transgenic plants had faster stem elongation during vegetative growth and earlier flowering than wild type (WT). Our studies focused on the transgenic tobacco phenotype.

Results: The levels of chlorophyll and soluble protein decreased and a lower seed biomass and reduced net photosynthetic rate (Pn) in transgenic plants. Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) and superoxide radicals (O 2 (·-) ) had higher levels in transgenics compared to controls. Transgenic plants also had enhanced sensitivity to oxidative stress. The transcriptome of 8-week-old plants was studied to detect molecular changes. Differentially expressed unigene analysis showed that ubiquitin-mediated proteolysis, cell growth, and death unigenes were upregulated. Unigenes related to photosynthesis, antioxidant activity, and nitrogen metabolism were downregulated. Combined with the expression analysis of senescence marker genes, these results indicate that senescence started in the leaves of the transgenic plants at the vegetative growth stage.

Conclusions: The antioxidative defense system was compromised and the accumulation of reactive oxygen species (ROS) played an important role in the premature aging of transgenic plants.

No MeSH data available.


Related in: MedlinePlus

Phenotypic variation of wild-type (WT) and transgenic plants at different developmental stages. A Variation in the height of WT and transgenic plants at different developmental stages, each line is the mean of five replicates. Differentletters indicate statistically significant differences at P ≤ 0.05, B eight-leaf period, and C filling period
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Fig2: Phenotypic variation of wild-type (WT) and transgenic plants at different developmental stages. A Variation in the height of WT and transgenic plants at different developmental stages, each line is the mean of five replicates. Differentletters indicate statistically significant differences at P ≤ 0.05, B eight-leaf period, and C filling period

Mentions: To determine growth differences in the WT, T3-1, T3-2 and T3-3, plant height, leaf area, and seed biomass were measured. At 8 weeks of age, the stem of transgenic plants had accelerated elongation with lengths reaching about 21 cm, whereas WT stems were approximately 2.0 cm in length (Fig. 2B). The transgenic plants flowered at about 10 weeks of age and had mature seeds at 18 weeks. At 18 weeks, the WT plants were still in full bloom. The heights of the tobacco plants were as follows: 108.0 cm, 81.7 cm, 84.0 cm and 83.3 cm for WT, T3-1, T3-2 and T3-3, respectively (Fig. 2C). Based on changes in height throughout the developmental process, the transgenic plants had faster development (Fig. 2A). At 8 weeks old, the transgenic plants showed no change in leaf biomass, a fivefold increase in stem biomass, and a twofold increase in root biomass (Table 2). There were 9–10 leaves per transgenic plant, whereas WT plants had 8 leaves. Leaf area was measured at different locations on transgenic and WT plants. Transgenic plants showed no changes in total leaf area but the functional leaf area significantly decreased and the upper leaf area significantly increased (Table 3).Fig. 2


The antioxidative defense system is involved in the premature senescence in transgenic tobacco (Nicotiana tabacum NC89).

Liu Y, Wang L, Liu H, Zhao R, Liu B, Fu Q, Zhang Y - Biol. Res. (2016)

Phenotypic variation of wild-type (WT) and transgenic plants at different developmental stages. A Variation in the height of WT and transgenic plants at different developmental stages, each line is the mean of five replicates. Differentletters indicate statistically significant differences at P ≤ 0.05, B eight-leaf period, and C filling period
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4930573&req=5

Fig2: Phenotypic variation of wild-type (WT) and transgenic plants at different developmental stages. A Variation in the height of WT and transgenic plants at different developmental stages, each line is the mean of five replicates. Differentletters indicate statistically significant differences at P ≤ 0.05, B eight-leaf period, and C filling period
Mentions: To determine growth differences in the WT, T3-1, T3-2 and T3-3, plant height, leaf area, and seed biomass were measured. At 8 weeks of age, the stem of transgenic plants had accelerated elongation with lengths reaching about 21 cm, whereas WT stems were approximately 2.0 cm in length (Fig. 2B). The transgenic plants flowered at about 10 weeks of age and had mature seeds at 18 weeks. At 18 weeks, the WT plants were still in full bloom. The heights of the tobacco plants were as follows: 108.0 cm, 81.7 cm, 84.0 cm and 83.3 cm for WT, T3-1, T3-2 and T3-3, respectively (Fig. 2C). Based on changes in height throughout the developmental process, the transgenic plants had faster development (Fig. 2A). At 8 weeks old, the transgenic plants showed no change in leaf biomass, a fivefold increase in stem biomass, and a twofold increase in root biomass (Table 2). There were 9–10 leaves per transgenic plant, whereas WT plants had 8 leaves. Leaf area was measured at different locations on transgenic and WT plants. Transgenic plants showed no changes in total leaf area but the functional leaf area significantly decreased and the upper leaf area significantly increased (Table 3).Fig. 2

Bottom Line: The levels of chlorophyll and soluble protein decreased and a lower seed biomass and reduced net photosynthetic rate (Pn) in transgenic plants.Combined with the expression analysis of senescence marker genes, these results indicate that senescence started in the leaves of the transgenic plants at the vegetative growth stage.The antioxidative defense system was compromised and the accumulation of reactive oxygen species (ROS) played an important role in the premature aging of transgenic plants.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, 61 Dai Zong Street, Tai'an, 271018, Shandong, People's Republic of China.

ABSTRACT

Background: α-Farnesene is a volatile sesquiterpene synthesized by the plant mevalonate (MVA) pathway through the action of α-farnesene synthase. The α-farnesene synthase 1 (MdAFS1) gene was isolated from apple peel (var. white winter pearmain), and transformed into tobacco (Nicotiana tabacum NC89). The transgenic plants had faster stem elongation during vegetative growth and earlier flowering than wild type (WT). Our studies focused on the transgenic tobacco phenotype.

Results: The levels of chlorophyll and soluble protein decreased and a lower seed biomass and reduced net photosynthetic rate (Pn) in transgenic plants. Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) and superoxide radicals (O 2 (·-) ) had higher levels in transgenics compared to controls. Transgenic plants also had enhanced sensitivity to oxidative stress. The transcriptome of 8-week-old plants was studied to detect molecular changes. Differentially expressed unigene analysis showed that ubiquitin-mediated proteolysis, cell growth, and death unigenes were upregulated. Unigenes related to photosynthesis, antioxidant activity, and nitrogen metabolism were downregulated. Combined with the expression analysis of senescence marker genes, these results indicate that senescence started in the leaves of the transgenic plants at the vegetative growth stage.

Conclusions: The antioxidative defense system was compromised and the accumulation of reactive oxygen species (ROS) played an important role in the premature aging of transgenic plants.

No MeSH data available.


Related in: MedlinePlus