Enhancement of Clover (<i>Trifolium alexandrinum</i> L.) Shade Tolerance and Nitrogen Fixation under Dense Stands-Based Cropping Systems
Improving legumes crops’ performance under dense stands shade environment (e.g., intercropped oats–clover) is needed to promote agroecological practices. Previous studies have revealed that ethylene produced by plants under dense standing conditions is among other factors that affect crops’ growth p...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-09-01
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| Series: | Agronomy |
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| Online Access: | https://www.mdpi.com/2073-4395/12/10/2332 |
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| author | Wael Toukabri Nouha Ferchichi Meriem Barbouchi Dorsaf Hlel Mohamed Jadlaoui Haithem Bahri Ridha Mhamdi Hatem Cheikh M’hamed Mohamed Annabi Darine Trabelsi |
| author_facet | Wael Toukabri Nouha Ferchichi Meriem Barbouchi Dorsaf Hlel Mohamed Jadlaoui Haithem Bahri Ridha Mhamdi Hatem Cheikh M’hamed Mohamed Annabi Darine Trabelsi |
| author_sort | Wael Toukabri |
| collection | DOAJ |
| description | Improving legumes crops’ performance under dense stands shade environment (e.g., intercropped oats–clover) is needed to promote agroecological practices. Previous studies have revealed that ethylene produced by plants under dense standing conditions is among other factors that affect crops’ growth performance and reduce legumes’ ability to fix nitrogen (N). Here, we identified a <i>Pseudomonas thivervalensis</i> strain T124 as a high ACC deaminase-producing bacterium and evaluated its potential ability to alleviate the effects of reduced light (RL) and exogenous ethylene applied as ACC (ethylene precursor) on clover growth and development under controlled conditions and field conditions at dense stands of clover and oats intercrops. RL decreases clover root and shoots biomass, whereas the T124 strain counteracted RL effects, enhancing clover tolerance to shade. Exogenous ACC reduced clover growth and chlorophyll content while inducing overaccumulation of reactive oxygen species (H<sub>2</sub>O<sub>2</sub> and O<sub>2</sub><sup>•−</sup>). ACC-elicited cellular stress was suppressed by strain T124, suggesting the role of bacterial ACC deaminase activity. Combined with <i>Rhizobium leguminosarum</i> strain T618 (the strain identified as being able to fix N in symbiosis with clover), T124 prevents early nodule senescence by improving nodule leghemoglobin and reducing nodule nitric oxide levels. Co-inoculation with T124 + T618 increased shoot N content (+24%) more than T618 alone. Field experiments revealed that intercropping decreases Photosynthetic Active Radiation (PAR) at the top of clover due to oats, affecting clover photosynthesis assimilation. Interestingly, under T124 inoculation treatments, clover net photosynthetic rate (Anet) and stomatal conductance (Gs) were found to improve relative to the control and T618 inoculation treatments. Clover exhibits improved growth performance in terms of branching and nodulation after T124 inoculation. Most significant improvements occurred with the mixing of the two strains. Data suggest that co-inoculation with <i>R. leguminosarum</i> T618 and <i>P. thivervalensis</i> T124 potentially decreases the interspecific competition between clover and oats intercrops by reducing ACC (ethylene precursor) levels. Our study revealed that co-inoculation of legumes with competitive rhizobia and ACC deaminase-producing PGPRs is an eco-friendly approach to improving intercropping systems’ performance. |
| first_indexed | 2024-03-09T20:54:18Z |
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| institution | Directory Open Access Journal |
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| language | English |
| last_indexed | 2024-03-09T20:54:18Z |
| publishDate | 2022-09-01 |
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| series | Agronomy |
| spelling | doaj.art-3c7992093c2442309546cebbb1c8a6102023-11-23T22:25:15ZengMDPI AGAgronomy2073-43952022-09-011210233210.3390/agronomy12102332Enhancement of Clover (<i>Trifolium alexandrinum</i> L.) Shade Tolerance and Nitrogen Fixation under Dense Stands-Based Cropping SystemsWael Toukabri0Nouha Ferchichi1Meriem Barbouchi2Dorsaf Hlel3Mohamed Jadlaoui4Haithem Bahri5Ridha Mhamdi6Hatem Cheikh M’hamed7Mohamed Annabi8Darine Trabelsi9Laboratory of Legumes and Sustainable Agrosystems, Centre of Biotechnology of Borj-Cedria (CBBC), BP 901, Hammam-Lif 2050, TunisiaLaboratory of Legumes and Sustainable Agrosystems, Centre of Biotechnology of Borj-Cedria (CBBC), BP 901, Hammam-Lif 2050, TunisiaAgronomic Sciences and Techniques Laboratory (LR16 INRAT 05), National Institute of Agricultural Research of Tunisia (INRAT), Carthage University, Ariana 2049, TunisiaNational Institute of Field Crops, Boussalem 8170, TunisiaNational Institute of Field Crops, Boussalem 8170, TunisiaAgronomic Sciences and Techniques Laboratory (LR16 INRAT 05), National Research Institute of Rural Engineering, Water and Forests (INRGREF), Carthage University, Ariana 2049, TunisiaLaboratory of Legumes and Sustainable Agrosystems, Centre of Biotechnology of Borj-Cedria (CBBC), BP 901, Hammam-Lif 2050, TunisiaAgronomic Sciences and Techniques Laboratory (LR16 INRAT 05), National Institute of Agricultural Research of Tunisia (INRAT), Carthage University, Ariana 2049, TunisiaAgronomic Sciences and Techniques Laboratory (LR16 INRAT 05), National Institute of Agricultural Research of Tunisia (INRAT), Carthage University, Ariana 2049, TunisiaLaboratory of Legumes and Sustainable Agrosystems, Centre of Biotechnology of Borj-Cedria (CBBC), BP 901, Hammam-Lif 2050, TunisiaImproving legumes crops’ performance under dense stands shade environment (e.g., intercropped oats–clover) is needed to promote agroecological practices. Previous studies have revealed that ethylene produced by plants under dense standing conditions is among other factors that affect crops’ growth performance and reduce legumes’ ability to fix nitrogen (N). Here, we identified a <i>Pseudomonas thivervalensis</i> strain T124 as a high ACC deaminase-producing bacterium and evaluated its potential ability to alleviate the effects of reduced light (RL) and exogenous ethylene applied as ACC (ethylene precursor) on clover growth and development under controlled conditions and field conditions at dense stands of clover and oats intercrops. RL decreases clover root and shoots biomass, whereas the T124 strain counteracted RL effects, enhancing clover tolerance to shade. Exogenous ACC reduced clover growth and chlorophyll content while inducing overaccumulation of reactive oxygen species (H<sub>2</sub>O<sub>2</sub> and O<sub>2</sub><sup>•−</sup>). ACC-elicited cellular stress was suppressed by strain T124, suggesting the role of bacterial ACC deaminase activity. Combined with <i>Rhizobium leguminosarum</i> strain T618 (the strain identified as being able to fix N in symbiosis with clover), T124 prevents early nodule senescence by improving nodule leghemoglobin and reducing nodule nitric oxide levels. Co-inoculation with T124 + T618 increased shoot N content (+24%) more than T618 alone. Field experiments revealed that intercropping decreases Photosynthetic Active Radiation (PAR) at the top of clover due to oats, affecting clover photosynthesis assimilation. Interestingly, under T124 inoculation treatments, clover net photosynthetic rate (Anet) and stomatal conductance (Gs) were found to improve relative to the control and T618 inoculation treatments. Clover exhibits improved growth performance in terms of branching and nodulation after T124 inoculation. Most significant improvements occurred with the mixing of the two strains. Data suggest that co-inoculation with <i>R. leguminosarum</i> T618 and <i>P. thivervalensis</i> T124 potentially decreases the interspecific competition between clover and oats intercrops by reducing ACC (ethylene precursor) levels. Our study revealed that co-inoculation of legumes with competitive rhizobia and ACC deaminase-producing PGPRs is an eco-friendly approach to improving intercropping systems’ performance.https://www.mdpi.com/2073-4395/12/10/2332ACC deaminaseintercroppingshadeethylenenodulationphotosynthesis |
| spellingShingle | Wael Toukabri Nouha Ferchichi Meriem Barbouchi Dorsaf Hlel Mohamed Jadlaoui Haithem Bahri Ridha Mhamdi Hatem Cheikh M’hamed Mohamed Annabi Darine Trabelsi Enhancement of Clover (<i>Trifolium alexandrinum</i> L.) Shade Tolerance and Nitrogen Fixation under Dense Stands-Based Cropping Systems Agronomy ACC deaminase intercropping shade ethylene nodulation photosynthesis |
| title | Enhancement of Clover (<i>Trifolium alexandrinum</i> L.) Shade Tolerance and Nitrogen Fixation under Dense Stands-Based Cropping Systems |
| title_full | Enhancement of Clover (<i>Trifolium alexandrinum</i> L.) Shade Tolerance and Nitrogen Fixation under Dense Stands-Based Cropping Systems |
| title_fullStr | Enhancement of Clover (<i>Trifolium alexandrinum</i> L.) Shade Tolerance and Nitrogen Fixation under Dense Stands-Based Cropping Systems |
| title_full_unstemmed | Enhancement of Clover (<i>Trifolium alexandrinum</i> L.) Shade Tolerance and Nitrogen Fixation under Dense Stands-Based Cropping Systems |
| title_short | Enhancement of Clover (<i>Trifolium alexandrinum</i> L.) Shade Tolerance and Nitrogen Fixation under Dense Stands-Based Cropping Systems |
| title_sort | enhancement of clover i trifolium alexandrinum i l shade tolerance and nitrogen fixation under dense stands based cropping systems |
| topic | ACC deaminase intercropping shade ethylene nodulation photosynthesis |
| url | https://www.mdpi.com/2073-4395/12/10/2332 |
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