Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (<i>Astragalus sinicus</i> L.)
Chinese milk vetch (<i>Astragalus sinicus</i> L.) is an important leguminous green manure that frequently suffers from seasonal drought. To improve its drought tolerance, the effects of rhizobia inoculation on drought tolerance and the underlying physiological mechanism were investigated...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-03-01
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| Series: | Agronomy |
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| Online Access: | https://www.mdpi.com/2073-4395/12/3/725 |
| _version_ | 1797473304081072128 |
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| author | Yajie Liu Zhenfei Guo Haifan Shi |
| author_facet | Yajie Liu Zhenfei Guo Haifan Shi |
| author_sort | Yajie Liu |
| collection | DOAJ |
| description | Chinese milk vetch (<i>Astragalus sinicus</i> L.) is an important leguminous green manure that frequently suffers from seasonal drought. To improve its drought tolerance, the effects of rhizobia inoculation on drought tolerance and the underlying physiological mechanism were investigated. Drought tolerance in combination with nitrogen assimilation, free amino acids, and polyamines was investigated in milk vetch with active nodules (AN), with inactive nodules (LN), or without nodules (NN). AN plants had increased drought tolerance compared to LN and NN plants. Glutamine synthetase (GS), glutamine 2-oxoglutarate amino transferase (GOGAT), and glutamate dehydrogenase (GDH) activities were decreased after drought, with higher levels in AN plants than in LN and NN plants under both control and drought stress conditions. Higher levels of proline (Pro), arginine (Ala), alanine (Ala), and glutamate (Glu) were observed in AN plants compared with LN and NN plants. Putrescine (Put), spermidine (Spd), and spermine (Spm) levels were increased in response to drought, and higher levels of Put and Spd were maintained in AN plants. It is suggested that active nodulation leads to increased drought tolerance in milk vetch, which is associated with improved nitrogen fixation and ammonium assimilation, which in turn lead to the promotion of free amino-acid and polyamine synthesis. |
| first_indexed | 2024-03-09T20:13:49Z |
| format | Article |
| id | doaj.art-ab6b6ddf06274282aacab51411e77c0d |
| institution | Directory Open Access Journal |
| issn | 2073-4395 |
| language | English |
| last_indexed | 2024-03-09T20:13:49Z |
| publishDate | 2022-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Agronomy |
| spelling | doaj.art-ab6b6ddf06274282aacab51411e77c0d2023-11-24T00:08:20ZengMDPI AGAgronomy2073-43952022-03-0112372510.3390/agronomy12030725Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (<i>Astragalus sinicus</i> L.)Yajie Liu0Zhenfei Guo1Haifan Shi2College of Grassland Science, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Grassland Science, Nanjing Agricultural University, Nanjing 210095, ChinaCollege of Grassland Science, Nanjing Agricultural University, Nanjing 210095, ChinaChinese milk vetch (<i>Astragalus sinicus</i> L.) is an important leguminous green manure that frequently suffers from seasonal drought. To improve its drought tolerance, the effects of rhizobia inoculation on drought tolerance and the underlying physiological mechanism were investigated. Drought tolerance in combination with nitrogen assimilation, free amino acids, and polyamines was investigated in milk vetch with active nodules (AN), with inactive nodules (LN), or without nodules (NN). AN plants had increased drought tolerance compared to LN and NN plants. Glutamine synthetase (GS), glutamine 2-oxoglutarate amino transferase (GOGAT), and glutamate dehydrogenase (GDH) activities were decreased after drought, with higher levels in AN plants than in LN and NN plants under both control and drought stress conditions. Higher levels of proline (Pro), arginine (Ala), alanine (Ala), and glutamate (Glu) were observed in AN plants compared with LN and NN plants. Putrescine (Put), spermidine (Spd), and spermine (Spm) levels were increased in response to drought, and higher levels of Put and Spd were maintained in AN plants. It is suggested that active nodulation leads to increased drought tolerance in milk vetch, which is associated with improved nitrogen fixation and ammonium assimilation, which in turn lead to the promotion of free amino-acid and polyamine synthesis.https://www.mdpi.com/2073-4395/12/3/725Chinese milk vetchdrought stressfree amino acidsnitrogen fixationpolyaminessymbiosis |
| spellingShingle | Yajie Liu Zhenfei Guo Haifan Shi Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (<i>Astragalus sinicus</i> L.) Agronomy Chinese milk vetch drought stress free amino acids nitrogen fixation polyamines symbiosis |
| title | Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (<i>Astragalus sinicus</i> L.) |
| title_full | Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (<i>Astragalus sinicus</i> L.) |
| title_fullStr | Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (<i>Astragalus sinicus</i> L.) |
| title_full_unstemmed | Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (<i>Astragalus sinicus</i> L.) |
| title_short | Rhizobium Symbiosis Leads to Increased Drought Tolerance in Chinese Milk Vetch (<i>Astragalus sinicus</i> L.) |
| title_sort | rhizobium symbiosis leads to increased drought tolerance in chinese milk vetch i astragalus sinicus i l |
| topic | Chinese milk vetch drought stress free amino acids nitrogen fixation polyamines symbiosis |
| url | https://www.mdpi.com/2073-4395/12/3/725 |
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