Bitter Melon (<i>Momordica charantia</i> L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense Pathways
High temperature is considered a critical abiotic stressor that is increasing continuously, which is severely affecting plant growth and development. The use of heat-resistant rootstock grafting is a viable technique that is practiced globally to improve plant resistance towards abiotic stresses. In...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2020-05-01
|
| Series: | Plants |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2223-7747/9/6/692 |
| _version_ | 1797566758257688576 |
|---|---|
| author | Mei-Qi Tao Mohammad Shah Jahan Kun Hou Sheng Shu Yu Wang Jin Sun Shi-Rong Guo |
| author_facet | Mei-Qi Tao Mohammad Shah Jahan Kun Hou Sheng Shu Yu Wang Jin Sun Shi-Rong Guo |
| author_sort | Mei-Qi Tao |
| collection | DOAJ |
| description | High temperature is considered a critical abiotic stressor that is increasing continuously, which is severely affecting plant growth and development. The use of heat-resistant rootstock grafting is a viable technique that is practiced globally to improve plant resistance towards abiotic stresses. In this experiment, we explored the efficacy of bitter melon rootstock and how it regulates photosynthesis and the antioxidant defense system to alleviate heat stress (42 °C/32 °C) in cucumber. Our results revealed that bitter-melon-grafted seedlings significantly relieved heat-induced growth inhibition and photoinhibition, maintained better photosynthesis activity, and accumulated a greater biomass than self-grafted seedlings. We measured the endogenous polyamine and hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) contents to determine the inherent mechanism responsible for these effects, and the results showed that heat stress induced a transient increase in polyamines and H<sub>2</sub>O<sub>2</sub> in the inner courtyard of grafted seedlings. This increment was greater and more robust in bitter-melon-grafted seedlings. In addition, the use of polyamine synthesis inhibitors MGBG (methylglyoxal bis-guanylhydrazone) and D-Arg (D-arginine), further confirmed that the production of H<sub>2</sub>O<sub>2</sub> under heat stress is mediated by the accumulation of endogenous polyamines. Moreover, compared with other treatments, the bitter-melon-grafted seedlings maintained high levels of antioxidant enzyme activity under high temperature conditions. However, these activities were significantly inhibited by polyamine synthesis inhibitors and H<sub>2</sub>O<sub>2</sub> scavengers (dimethylthiourea, DMTU), indicating that bitter melon rootstock not only maintained better photosynthetic activity under conditions of high temperature stress but also mediated the production of H<sub>2</sub>O<sub>2</sub> through the regulation of the high level of endogenous polyamines, thereby boosting the antioxidant defense system and comprehensively improving the heat tolerance of cucumber seedlings. Taken together, these results indicate that grafting with a resistant cultivar is a promising alternative tool for reducing stress-induced damage. |
| first_indexed | 2024-03-10T19:31:01Z |
| format | Article |
| id | doaj.art-c3e0f460fe6948a5997309a7f0b3b8e7 |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-03-10T19:31:01Z |
| publishDate | 2020-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-c3e0f460fe6948a5997309a7f0b3b8e72023-11-20T02:07:57ZengMDPI AGPlants2223-77472020-05-019669210.3390/plants9060692Bitter Melon (<i>Momordica charantia</i> L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense PathwaysMei-Qi Tao0Mohammad Shah Jahan1Kun Hou2Sheng Shu3Yu Wang4Jin Sun5Shi-Rong Guo6Key Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaKey Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaKey Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaKey Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaKey Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaKey Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaKey Laboratory of Southern Vegetable Crop Genetic Improvement in Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, ChinaHigh temperature is considered a critical abiotic stressor that is increasing continuously, which is severely affecting plant growth and development. The use of heat-resistant rootstock grafting is a viable technique that is practiced globally to improve plant resistance towards abiotic stresses. In this experiment, we explored the efficacy of bitter melon rootstock and how it regulates photosynthesis and the antioxidant defense system to alleviate heat stress (42 °C/32 °C) in cucumber. Our results revealed that bitter-melon-grafted seedlings significantly relieved heat-induced growth inhibition and photoinhibition, maintained better photosynthesis activity, and accumulated a greater biomass than self-grafted seedlings. We measured the endogenous polyamine and hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) contents to determine the inherent mechanism responsible for these effects, and the results showed that heat stress induced a transient increase in polyamines and H<sub>2</sub>O<sub>2</sub> in the inner courtyard of grafted seedlings. This increment was greater and more robust in bitter-melon-grafted seedlings. In addition, the use of polyamine synthesis inhibitors MGBG (methylglyoxal bis-guanylhydrazone) and D-Arg (D-arginine), further confirmed that the production of H<sub>2</sub>O<sub>2</sub> under heat stress is mediated by the accumulation of endogenous polyamines. Moreover, compared with other treatments, the bitter-melon-grafted seedlings maintained high levels of antioxidant enzyme activity under high temperature conditions. However, these activities were significantly inhibited by polyamine synthesis inhibitors and H<sub>2</sub>O<sub>2</sub> scavengers (dimethylthiourea, DMTU), indicating that bitter melon rootstock not only maintained better photosynthetic activity under conditions of high temperature stress but also mediated the production of H<sub>2</sub>O<sub>2</sub> through the regulation of the high level of endogenous polyamines, thereby boosting the antioxidant defense system and comprehensively improving the heat tolerance of cucumber seedlings. Taken together, these results indicate that grafting with a resistant cultivar is a promising alternative tool for reducing stress-induced damage.https://www.mdpi.com/2223-7747/9/6/692heat stressgraftingcucumberbitter-melon rootstockpolyaminesphotosynthesis |
| spellingShingle | Mei-Qi Tao Mohammad Shah Jahan Kun Hou Sheng Shu Yu Wang Jin Sun Shi-Rong Guo Bitter Melon (<i>Momordica charantia</i> L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense Pathways Plants heat stress grafting cucumber bitter-melon rootstock polyamines photosynthesis |
| title | Bitter Melon (<i>Momordica charantia</i> L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense Pathways |
| title_full | Bitter Melon (<i>Momordica charantia</i> L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense Pathways |
| title_fullStr | Bitter Melon (<i>Momordica charantia</i> L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense Pathways |
| title_full_unstemmed | Bitter Melon (<i>Momordica charantia</i> L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense Pathways |
| title_short | Bitter Melon (<i>Momordica charantia</i> L.) Rootstock Improves the Heat Tolerance of Cucumber by Regulating Photosynthetic and Antioxidant Defense Pathways |
| title_sort | bitter melon i momordica charantia i l rootstock improves the heat tolerance of cucumber by regulating photosynthetic and antioxidant defense pathways |
| topic | heat stress grafting cucumber bitter-melon rootstock polyamines photosynthesis |
| url | https://www.mdpi.com/2223-7747/9/6/692 |
| work_keys_str_mv | AT meiqitao bittermelonimomordicacharantiailrootstockimprovestheheattoleranceofcucumberbyregulatingphotosyntheticandantioxidantdefensepathways AT mohammadshahjahan bittermelonimomordicacharantiailrootstockimprovestheheattoleranceofcucumberbyregulatingphotosyntheticandantioxidantdefensepathways AT kunhou bittermelonimomordicacharantiailrootstockimprovestheheattoleranceofcucumberbyregulatingphotosyntheticandantioxidantdefensepathways AT shengshu bittermelonimomordicacharantiailrootstockimprovestheheattoleranceofcucumberbyregulatingphotosyntheticandantioxidantdefensepathways AT yuwang bittermelonimomordicacharantiailrootstockimprovestheheattoleranceofcucumberbyregulatingphotosyntheticandantioxidantdefensepathways AT jinsun bittermelonimomordicacharantiailrootstockimprovestheheattoleranceofcucumberbyregulatingphotosyntheticandantioxidantdefensepathways AT shirongguo bittermelonimomordicacharantiailrootstockimprovestheheattoleranceofcucumberbyregulatingphotosyntheticandantioxidantdefensepathways |