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Su X, Zhang L, Meng H, Wang H, Zhao J, Sun X, Song X, Zhang X, Mao L. Long-term conservation tillage increase cotton rhizosphere sequestration of soil organic carbon by changing specific microbial CO 2 fixation pathways in coastal saline soil. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 358:120743. [PMID: 38626484 DOI: 10.1016/j.jenvman.2024.120743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 02/27/2024] [Accepted: 03/19/2024] [Indexed: 04/18/2024]
Abstract
Coastal saline soil is an important reserve resource for arable land globally. Data from 10 years of continuous stubble return and subsoiling experiments have revealed that these two conservation tillage measures significantly improve cotton rhizosphere soil organic carbon sequestration in coastal saline soil. However, the contribution of microbial fixation of atmospheric carbon dioxide (CO2) has remained unclear. Here, metagenomics and metabolomics analyses were used to deeply explore the microbial CO2 fixation process in rhizosphere soil of coastal saline cotton fields under long-term stubble return and subsoiling. Metagenomics analysis showed that stubble return and subsoiling mainly optimized CO2 fixing microorganism (CFM) communities by increasing the abundance of Acidobacteria, Gemmatimonadetes, and Chloroflexi, and improving composition diversity. Conjoint metagenomics and metabolomics analyses investigated the effects of stubble return and subsoiling on the reverse tricarboxylic acid (rTCA) cycle. The conversion of citrate to oxaloacetate was inhibited in the citrate cleavage reaction of the rTCA cycle. More citrate was converted to acetyl-CoA, which enhanced the subsequent CO2 fixation process of acetyl-CoA conversion to pyruvate. In the rTCA cycle reductive carboxylation reaction from 2-oxoglutarate to isocitrate, synthesis of the oxalosuccinate intermediate product was inhibited, with strengthened CO2 fixation involving the direct conversion of 2-oxoglutarate to isocitrate. The collective results demonstrate that stubble return and subsoiling optimizes rhizosphere CFM communities by increasing microbial diversity, in turn increasing CO2 fixation by enhancing the utilization of rTCA and 3-hydroxypropionate/4-hydroxybutyrate cycles by CFMs. These events increase the microbial CO2 fixation in the cotton rhizosphere, thereby promoting the accumulation of microbial biomass, and ultimately improving rhizosphere soil organic carbon. This study clarifies the impact of conservation tillage measures on microbial CO2 fixation in cotton rhizosphere of coastal saline soil, and provides fundamental data for the improvement of carbon sequestration in saline soil in agricultural ecosystems.
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Affiliation(s)
- Xunya Su
- Shandong Agricultural University, Agronomy College, Taian, Shandong, 271018, China.
| | - Le Zhang
- China Agricultural University, Agronomy College, Beijing, 100193, China.
| | - Hao Meng
- Shandong Agricultural University, Agronomy College, Taian, Shandong, 271018, China.
| | - Han Wang
- Shandong Agricultural University, Agronomy College, Taian, Shandong, 271018, China.
| | - Jiaxue Zhao
- Shandong Agricultural University, Agronomy College, Taian, Shandong, 271018, China.
| | - Xuezhen Sun
- Shandong Agricultural University, Agronomy College, Taian, Shandong, 271018, China.
| | - Xianliang Song
- Shandong Agricultural University, Agronomy College, Taian, Shandong, 271018, China.
| | - Xiaopei Zhang
- Shandong Agricultural University, Agronomy College, Taian, Shandong, 271018, China.
| | - Lili Mao
- Shandong Agricultural University, Agronomy College, Taian, Shandong, 271018, China.
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Li Z, Xiao Y, Zhou K, Jin X, Li W, Li W, Zhang L, Wang J, Hu R, Lin L. Water extract of Fagopyrum dibotrys (D. Don) Hara straw increases selenium accumulation in peach seedlings under selenium-contaminated soil. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2023; 26:569-578. [PMID: 37684742 DOI: 10.1080/15226514.2023.2255287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
To promote the selenium (Se) uptakes in fruit trees under Se-contaminated soil, the effects of water extract of Fagopyrum dibotrys (D. Don) Hara straw on the Se accumulation in peach seedlings under selenium-contaminated soil were studied. The results showed that the root biomass, chlorophyll content, activities of antioxidant enzymes, and soluble protein content of peach seedlings were increased by the F. dibotrys straw extract. The different forms of Se (total Se, inorganic Se, and organic Se) were also increased in peach seedlings following treatment with the F. dibotrys straw extract. The highest total shoot Se content was treated by the 300-fold dilution of F. dibotrys straw, which was 30.87% higher than the control. The F. dibotrys straw extract also increased the activities of adenosine triphosphate sulfurase (ATPS), and adenosine 5'-phosphosulfate reductase (APR) in peach seedlings, but decreased the activity of serine acetyltransferase (SAT). Additionally, correlation and grey relational analyses revealed that chlorophyll a content, APR activity, and root biomass were closely associated with the total shoot Se content. Overall, this study shows that the water extract of F. dibotrys straw can promote Se uptake in peach seedlings, and 300-fold dilution is the most suitable concentration.
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Affiliation(s)
- Zhiyu Li
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
| | - Yunying Xiao
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
| | - Kexuan Zhou
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
| | - Xin Jin
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
| | - Wan Li
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
| | - Wanzhi Li
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
| | - Lu Zhang
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
| | - Jin Wang
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
| | - Rongping Hu
- Institute of Agricultural Resources and Environment, Sichuan Academy of Agricultural Sciences, Chengdu, China
| | - Lijin Lin
- College of Horticulture, Sichuan Agricultural University, Chengdu, China
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