Overexpression of 7-hydroxymethyl Chlorophyll <i>a</i> Reductase from Cucumber in Tobacco Accelerates Dark-Induced Chlorophyll Degradation
7-hydroxymethyl chlorophyll (Chl) <i>a</i> reductase (HCAR) plays critical roles in the Chl cycle and degradation during leaf senescence, however, its function in horticultural crops remains unknown. Here, we identified an <i>HCAR</i> gene (<i>CsHCAR</i>) from cuc...
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MDPI AG
2021-08-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/10/9/1820 |
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| author | Weikang Liu Guangling Chen Jiaqi Chen Mohammad Shah Jahan Shirong Guo Yu Wang Jin Sun |
| author_facet | Weikang Liu Guangling Chen Jiaqi Chen Mohammad Shah Jahan Shirong Guo Yu Wang Jin Sun |
| author_sort | Weikang Liu |
| collection | DOAJ |
| description | 7-hydroxymethyl chlorophyll (Chl) <i>a</i> reductase (HCAR) plays critical roles in the Chl cycle and degradation during leaf senescence, however, its function in horticultural crops remains unknown. Here, we identified an <i>HCAR</i> gene (<i>CsHCAR</i>) from cucumber (<i>Cucumis sativus</i> L.) and investigated its roles in response to dark-induced Chl degradation. <i>CsHCAR</i> encoded 459 amino acids, which were orthologous to Arabidopsis HCAR, had the conserved domains, and localized in the chloroplast. Gene expression analysis showed that <i>CsHCAR</i> expression was the highest in senescent leaves and was responsive to different stresses and phytohormone treatments. Overexpression of <i>CsHCAR</i> in tobacco accelerated dark-induced Chl degradation through enhancing the expression of Chl catabolic genes. After 10 d of darkness treatment, the biomass of <i>CsHCAR</i> overexpression plants was reduced. Furthermore, the value of net photosynthetic rate, maximum quantum yield of photosystem II, and effective quantum yield of photosystem II in <i>CsHCAR</i> overexpression plants was significantly reduced in comparison to that in wild-type (WT) plants. The photosynthetic protein content, including Lhcb1, Lhcb2, Lhcb4, RbcS, and RbcL in <i>CsHCAR</i> overexpression plants exhibited a lower level as compared to that observed in WT plants. In addition, the expression of genes encoding these proteins in <i>CsHCAR</i> overexpression plants was significantly lower than that in WT plants. Moreover, <i>CsHCAR</i> overexpression plants inhibited the dark-induced accumulation of reactive oxygen species (ROS). These results indicate that <i>CsHCAR</i> affects the stability of photosynthetic proteins in chloroplasts, positively regulates Chl degradation, and plays an important role in maintaining ROS homeostasis in leaves. |
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| language | English |
| last_indexed | 2024-03-10T07:17:06Z |
| publishDate | 2021-08-01 |
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| series | Plants |
| spelling | doaj.art-2137f96cf104417596909416288183402023-11-22T14:52:14ZengMDPI AGPlants2223-77472021-08-01109182010.3390/plants10091820Overexpression of 7-hydroxymethyl Chlorophyll <i>a</i> Reductase from Cucumber in Tobacco Accelerates Dark-Induced Chlorophyll DegradationWeikang Liu0Guangling Chen1Jiaqi Chen2Mohammad Shah Jahan3Shirong Guo4Yu Wang5Jin Sun6College of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Horticulture, Nanjing Agricultural University, Nanjing 210095, China7-hydroxymethyl chlorophyll (Chl) <i>a</i> reductase (HCAR) plays critical roles in the Chl cycle and degradation during leaf senescence, however, its function in horticultural crops remains unknown. Here, we identified an <i>HCAR</i> gene (<i>CsHCAR</i>) from cucumber (<i>Cucumis sativus</i> L.) and investigated its roles in response to dark-induced Chl degradation. <i>CsHCAR</i> encoded 459 amino acids, which were orthologous to Arabidopsis HCAR, had the conserved domains, and localized in the chloroplast. Gene expression analysis showed that <i>CsHCAR</i> expression was the highest in senescent leaves and was responsive to different stresses and phytohormone treatments. Overexpression of <i>CsHCAR</i> in tobacco accelerated dark-induced Chl degradation through enhancing the expression of Chl catabolic genes. After 10 d of darkness treatment, the biomass of <i>CsHCAR</i> overexpression plants was reduced. Furthermore, the value of net photosynthetic rate, maximum quantum yield of photosystem II, and effective quantum yield of photosystem II in <i>CsHCAR</i> overexpression plants was significantly reduced in comparison to that in wild-type (WT) plants. The photosynthetic protein content, including Lhcb1, Lhcb2, Lhcb4, RbcS, and RbcL in <i>CsHCAR</i> overexpression plants exhibited a lower level as compared to that observed in WT plants. In addition, the expression of genes encoding these proteins in <i>CsHCAR</i> overexpression plants was significantly lower than that in WT plants. Moreover, <i>CsHCAR</i> overexpression plants inhibited the dark-induced accumulation of reactive oxygen species (ROS). These results indicate that <i>CsHCAR</i> affects the stability of photosynthetic proteins in chloroplasts, positively regulates Chl degradation, and plays an important role in maintaining ROS homeostasis in leaves.https://www.mdpi.com/2223-7747/10/9/1820cucumberchlorophyll degradationdarkness7-hydroxymethyl chlorophyll <i>a</i> reductase (HCAR)leaf senescence |
| spellingShingle | Weikang Liu Guangling Chen Jiaqi Chen Mohammad Shah Jahan Shirong Guo Yu Wang Jin Sun Overexpression of 7-hydroxymethyl Chlorophyll <i>a</i> Reductase from Cucumber in Tobacco Accelerates Dark-Induced Chlorophyll Degradation Plants cucumber chlorophyll degradation darkness 7-hydroxymethyl chlorophyll <i>a</i> reductase (HCAR) leaf senescence |
| title | Overexpression of 7-hydroxymethyl Chlorophyll <i>a</i> Reductase from Cucumber in Tobacco Accelerates Dark-Induced Chlorophyll Degradation |
| title_full | Overexpression of 7-hydroxymethyl Chlorophyll <i>a</i> Reductase from Cucumber in Tobacco Accelerates Dark-Induced Chlorophyll Degradation |
| title_fullStr | Overexpression of 7-hydroxymethyl Chlorophyll <i>a</i> Reductase from Cucumber in Tobacco Accelerates Dark-Induced Chlorophyll Degradation |
| title_full_unstemmed | Overexpression of 7-hydroxymethyl Chlorophyll <i>a</i> Reductase from Cucumber in Tobacco Accelerates Dark-Induced Chlorophyll Degradation |
| title_short | Overexpression of 7-hydroxymethyl Chlorophyll <i>a</i> Reductase from Cucumber in Tobacco Accelerates Dark-Induced Chlorophyll Degradation |
| title_sort | overexpression of 7 hydroxymethyl chlorophyll i a i reductase from cucumber in tobacco accelerates dark induced chlorophyll degradation |
| topic | cucumber chlorophyll degradation darkness 7-hydroxymethyl chlorophyll <i>a</i> reductase (HCAR) leaf senescence |
| url | https://www.mdpi.com/2223-7747/10/9/1820 |
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