Ken E. Giller, Euan K. James, Julie Ardley, Murray J. Unkovich
{"title":"科学迷失方向:谷物和其他非豆科植物中微生物固定 N2 的实例","authors":"Ken E. Giller, Euan K. James, Julie Ardley, Murray J. Unkovich","doi":"10.1007/s11104-024-07001-1","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Background</h3><p>Despite more than 50 years of research, no robust evidence suggests that inoculation of cereals and other non-legumes with free-living and/or endophytic bacteria leads to fixation of agronomically significant quantities of dinitrogen gas (N<sub>2</sub>) from the atmosphere. A plethora of new products claims to increase the growth and yields of major cereals and other crops through stimulating N<sub>2</sub>-fixation by inoculating with bacteria.</p><h3 data-test=\"abstract-sub-heading\">Scope</h3><p>We review the literature on N<sub>2</sub>-fixation by bacteria in the rhizosphere and as endophytes in non-legume plants. We find no unequivocal evidence that these bacteria fix agriculturally significant amounts of N<sub>2</sub> from the atmosphere in non-legumes. Research since the 1930s has followed repeated, overlapping cycles that have concluded that plant-growth-promoting hormones were the primary reason for crop response to microbial inoculants.</p><h3 data-test=\"abstract-sub-heading\">Conclusion</h3><p>We contend that regulations are required to prevent the sale of inoculant products with unsubstantiated and spurious claims. Such regulations should require that unequivocal evidence is provided and independently verified, that: (i) the inoculant bacterium can fix N<sub>2</sub> from the atmosphere (i.e. that it possesses all the genes required to make nitrogenase), (ii) it has a clear mechanism to protect nitrogenase from poisoning by free oxygen, (iii) the bacterium is present in sufficient numbers throughout the growth cycle of the plant, (iv) that enhanced respiration can be detected from the putative N<sub>2</sub>-fixing tissues, (v) that inoculation of the non-legume growing in an N-free medium leads to prolific growth and accumulation of nitrogen, and (vi) more than one method is used to confirm quantitatively significant inputs from N<sub>2</sub>-fixation in the field.</p>","PeriodicalId":20223,"journal":{"name":"Plant and Soil","volume":null,"pages":null},"PeriodicalIF":3.9000,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Science losing its way: examples from the realm of microbial N2-fixation in cereals and other non-legumes\",\"authors\":\"Ken E. Giller, Euan K. James, Julie Ardley, Murray J. Unkovich\",\"doi\":\"10.1007/s11104-024-07001-1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<h3 data-test=\\\"abstract-sub-heading\\\">Background</h3><p>Despite more than 50 years of research, no robust evidence suggests that inoculation of cereals and other non-legumes with free-living and/or endophytic bacteria leads to fixation of agronomically significant quantities of dinitrogen gas (N<sub>2</sub>) from the atmosphere. A plethora of new products claims to increase the growth and yields of major cereals and other crops through stimulating N<sub>2</sub>-fixation by inoculating with bacteria.</p><h3 data-test=\\\"abstract-sub-heading\\\">Scope</h3><p>We review the literature on N<sub>2</sub>-fixation by bacteria in the rhizosphere and as endophytes in non-legume plants. We find no unequivocal evidence that these bacteria fix agriculturally significant amounts of N<sub>2</sub> from the atmosphere in non-legumes. Research since the 1930s has followed repeated, overlapping cycles that have concluded that plant-growth-promoting hormones were the primary reason for crop response to microbial inoculants.</p><h3 data-test=\\\"abstract-sub-heading\\\">Conclusion</h3><p>We contend that regulations are required to prevent the sale of inoculant products with unsubstantiated and spurious claims. Such regulations should require that unequivocal evidence is provided and independently verified, that: (i) the inoculant bacterium can fix N<sub>2</sub> from the atmosphere (i.e. that it possesses all the genes required to make nitrogenase), (ii) it has a clear mechanism to protect nitrogenase from poisoning by free oxygen, (iii) the bacterium is present in sufficient numbers throughout the growth cycle of the plant, (iv) that enhanced respiration can be detected from the putative N<sub>2</sub>-fixing tissues, (v) that inoculation of the non-legume growing in an N-free medium leads to prolific growth and accumulation of nitrogen, and (vi) more than one method is used to confirm quantitatively significant inputs from N<sub>2</sub>-fixation in the field.</p>\",\"PeriodicalId\":20223,\"journal\":{\"name\":\"Plant and Soil\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":3.9000,\"publicationDate\":\"2024-10-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Plant and Soil\",\"FirstCategoryId\":\"97\",\"ListUrlMain\":\"https://doi.org/10.1007/s11104-024-07001-1\",\"RegionNum\":2,\"RegionCategory\":\"农林科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"AGRONOMY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Plant and Soil","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1007/s11104-024-07001-1","RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRONOMY","Score":null,"Total":0}
Science losing its way: examples from the realm of microbial N2-fixation in cereals and other non-legumes
Background
Despite more than 50 years of research, no robust evidence suggests that inoculation of cereals and other non-legumes with free-living and/or endophytic bacteria leads to fixation of agronomically significant quantities of dinitrogen gas (N2) from the atmosphere. A plethora of new products claims to increase the growth and yields of major cereals and other crops through stimulating N2-fixation by inoculating with bacteria.
Scope
We review the literature on N2-fixation by bacteria in the rhizosphere and as endophytes in non-legume plants. We find no unequivocal evidence that these bacteria fix agriculturally significant amounts of N2 from the atmosphere in non-legumes. Research since the 1930s has followed repeated, overlapping cycles that have concluded that plant-growth-promoting hormones were the primary reason for crop response to microbial inoculants.
Conclusion
We contend that regulations are required to prevent the sale of inoculant products with unsubstantiated and spurious claims. Such regulations should require that unequivocal evidence is provided and independently verified, that: (i) the inoculant bacterium can fix N2 from the atmosphere (i.e. that it possesses all the genes required to make nitrogenase), (ii) it has a clear mechanism to protect nitrogenase from poisoning by free oxygen, (iii) the bacterium is present in sufficient numbers throughout the growth cycle of the plant, (iv) that enhanced respiration can be detected from the putative N2-fixing tissues, (v) that inoculation of the non-legume growing in an N-free medium leads to prolific growth and accumulation of nitrogen, and (vi) more than one method is used to confirm quantitatively significant inputs from N2-fixation in the field.
期刊介绍:
Plant and Soil publishes original papers and review articles exploring the interface of plant biology and soil sciences, and that enhance our mechanistic understanding of plant-soil interactions. We focus on the interface of plant biology and soil sciences, and seek those manuscripts with a strong mechanistic component which develop and test hypotheses aimed at understanding underlying mechanisms of plant-soil interactions. Manuscripts can include both fundamental and applied aspects of mineral nutrition, plant water relations, symbiotic and pathogenic plant-microbe interactions, root anatomy and morphology, soil biology, ecology, agrochemistry and agrophysics, as long as they are hypothesis-driven and enhance our mechanistic understanding. Articles including a major molecular or modelling component also fall within the scope of the journal. All contributions appear in the English language, with consistent spelling, using either American or British English.