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BULLETIN 1
ILRI scientists develop new guideline on pioneer-positive deviance for agricultural extension in Ethiopia
ILRI scientists develop new guideline on pioneer-positive deviance for agricultural extension in Ethiopia
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CGIAR October 24 2025
Scientists at the International Livestock Research Institute (ILRI) have published a new guideline on pioneer-positive deviance for the agricultural extension system in Ethiopia.
The document provides guidance on how to use approaches that look for solutions on the ground, rather than imposing them, and work with farmers in building on those in a genuine co-design process with equal collaboration of all.
This approach is based on positive deviance theory and identifies pioneer households for sustainable livestock solutions.
What is pioneer-positive deviance?
Pioneer-positive deviance is an approach developed by a team of scientists at ILRI to address issues of adaptation to climate change.
It is an evolution of the original concept of positive deviance originating in public health research.
It focuses on identifying and learning from individuals, groups, or households who find unique, successful solutions to common challenges despite having no additional resources or advantages.
By studying these “positive deviants”, communities can discover locally effective practices that can be adopted and scaled, making solutions more sustainable and tailored to specific needs.
Positive deviance has been used in areas like public health, education, and social change to solve complex problems from within the community.
This resource will be useful for development practitioners, extension workers, and educators in colleges and universities in Ethiopia.
Acknowledgements
The work was partly financed by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) and conducted as part of the CGIAR Initiative on Livestock and Climate, the CGIAR Sustainable Animal and Aquatic Foods program and the CGIAR Climate Action program.
See https://www.cgiar.org/news-events/news/ilri-scientists-develop-new-guideline-on-pioneer-positive-deviance-for-agricultural-extension-in-ethiopia/
The document provides guidance on how to use approaches that look for solutions on the ground, rather than imposing them, and work with farmers in building on those in a genuine co-design process with equal collaboration of all.
This approach is based on positive deviance theory and identifies pioneer households for sustainable livestock solutions.
What is pioneer-positive deviance?
Pioneer-positive deviance is an approach developed by a team of scientists at ILRI to address issues of adaptation to climate change.
It is an evolution of the original concept of positive deviance originating in public health research.
It focuses on identifying and learning from individuals, groups, or households who find unique, successful solutions to common challenges despite having no additional resources or advantages.
By studying these “positive deviants”, communities can discover locally effective practices that can be adopted and scaled, making solutions more sustainable and tailored to specific needs.
Positive deviance has been used in areas like public health, education, and social change to solve complex problems from within the community.
This resource will be useful for development practitioners, extension workers, and educators in colleges and universities in Ethiopia.
Acknowledgements
The work was partly financed by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) and conducted as part of the CGIAR Initiative on Livestock and Climate, the CGIAR Sustainable Animal and Aquatic Foods program and the CGIAR Climate Action program.
See https://www.cgiar.org/news-events/news/ilri-scientists-develop-new-guideline-on-pioneer-positive-deviance-for-agricultural-extension-in-ethiopia/
BULLETIN 2
Iowa State Scientists Use Gene Editing to Explore Chromosomes of Agrobacterium tumefaciens
Iowa State Scientists Use Gene Editing to Explore Chromosomes of Agrobacterium tumefaciens
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Iowa State University Professor Kan Wang studies Agrobacterium. (Photo Source: Brooklyn Draisey/Iowa Capital Dispatch)
ISAAA October 22, 2025
Researchers at Iowa State University (ISU) have made discoveries about Agrobacterium tumefaciens, the bacterium responsible for the creation of genetically modified (GM) crops. Led by Professor Kan Wang of ISU's Agronomy and Biotechnology, the team explored how changes in the bacterium's DNA affect its ability to infect plants and influence their growth.
Agrobacterium tumefaciens is also the foundation of genetic engineering in agriculture, which allows scientists to insert foreign genes into crops. “All of the GMOs on the market were made by Agrobacterium,” Wang explained. While studying as a graduate student, Wang learned Agrobacterium's unique ability to transfer its own DNA into plant cells and integrate it into their chromosomes. This led the researchers to use gene editing methods to “disarm” the genes responsible for tumor growth in plants and replace them with a different gene.
Using gene editing, Wang's team “played around” with Agrobacterium's chromosomes by deleting certain genes and adding others in. They found that rearranging them altered the bacterium's growth and infection capabilities. The research also revealed that Agrobacterium with fused chromosomes grew faster but were less effective at infecting plants. Wang said the research could lead to improved biocontrol strategies for farmers and better biotechnological tools for scientists.
For more information, read the article from Iowa Capital Dispatch.
See https://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=21559
Agrobacterium tumefaciens is also the foundation of genetic engineering in agriculture, which allows scientists to insert foreign genes into crops. “All of the GMOs on the market were made by Agrobacterium,” Wang explained. While studying as a graduate student, Wang learned Agrobacterium's unique ability to transfer its own DNA into plant cells and integrate it into their chromosomes. This led the researchers to use gene editing methods to “disarm” the genes responsible for tumor growth in plants and replace them with a different gene.
Using gene editing, Wang's team “played around” with Agrobacterium's chromosomes by deleting certain genes and adding others in. They found that rearranging them altered the bacterium's growth and infection capabilities. The research also revealed that Agrobacterium with fused chromosomes grew faster but were less effective at infecting plants. Wang said the research could lead to improved biocontrol strategies for farmers and better biotechnological tools for scientists.
For more information, read the article from Iowa Capital Dispatch.
See https://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=21559
SCIENTIFIC NEWS
Ubiquitin-mediated degradation restricts spatiotemporal accumulation of the cytoplasmic male sterility protein WA352 to anthers in rice
Zixu Zhang, Zhi Ding, Xueye Feng, Jingjing Huang, Xu Peng, Yubin Xiao, Wubei Zong, Zhe Zhao, Yao-Guang Liu, Yongyao Xie, and Letian Chen
PNAS October 16, 2025; 122 (42) e2504381122; https://doi.org/10.1073/pnas.2504381122
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Significance
Cytoplasmic male sterility (CMS) in plants helps breeders produce high-yield hybrid varieties. Genes that cause CMS are expressed throughout the plant, but the proteins they encode preferentially accumulate in anthers; how this occurs remains an unsolved mystery. Here, we show that mitochondrial F-box proteins participate in ubiquitination of the N-terminal transmembrane region of the CMS protein WA352, targeting it for degradation in vegetative tissues. However, the genes encoding these F-box proteins are specifically down-regulated at the microspore mother cell stage, allowing WA352 to accumulate and hijack the cytochrome c oxidase subunit COX11, causing a burst of reactive oxygen species in the anther and consequent CMS. These findings reveal a mechanism regulating the specific accumulation of this CMS protein in mitochondria.
Abstract
Cytoplasmic male sterility (CMS) is caused by mitochondrial genes that are constitutively expressed in plant tissues, although the encoded proteins preferentially accumulate in anthers. The mechanisms regulating CMS protein accumulation remain unclear. Here, we explored this process using wild-abortive CMS (CMS-WA) rice (Oryza sativa). We show that WA352, the causal protein of CMS-WA, is degraded by the ubiquitin–proteasome system (UPS). Structural analysis and protein truncation assays revealed that the N terminus of WA352 is critical for its anchoring to the inner mitochondrial membrane and its UPS-mediated degradation. Functional complementation confirmed that WA352151–352, lacking the N-terminal domain, accumulates constitutively in vegetative tissues, causing a reactive oxygen species burst and retarding rice growth. We further identified three mitochondrion-localized F-box proteins that participate in WA352 ubiquitination and degradation. Our findings demonstrate that UPS-mediated regulation restricts WA352 accumulation to anthers, allowing it to specifically disrupt anther development, thus helping to explain the male-specific effects of CMS genes in plants.
See: https://www.pnas.org/doi/10.1073/pnas.2504381122
Cytoplasmic male sterility (CMS) is caused by mitochondrial genes that are constitutively expressed in plant tissues, although the encoded proteins preferentially accumulate in anthers. The mechanisms regulating CMS protein accumulation remain unclear. Here, we explored this process using wild-abortive CMS (CMS-WA) rice (Oryza sativa). We show that WA352, the causal protein of CMS-WA, is degraded by the ubiquitin–proteasome system (UPS). Structural analysis and protein truncation assays revealed that the N terminus of WA352 is critical for its anchoring to the inner mitochondrial membrane and its UPS-mediated degradation. Functional complementation confirmed that WA352151–352, lacking the N-terminal domain, accumulates constitutively in vegetative tissues, causing a reactive oxygen species burst and retarding rice growth. We further identified three mitochondrion-localized F-box proteins that participate in WA352 ubiquitination and degradation. Our findings demonstrate that UPS-mediated regulation restricts WA352 accumulation to anthers, allowing it to specifically disrupt anther development, thus helping to explain the male-specific effects of CMS genes in plants.
See: https://www.pnas.org/doi/10.1073/pnas.2504381122
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Figure:
Expression profiling and structural analysis of the CMS protein WA352.
(A) The mitochondrial gene WA352 is constitutively expressed in anthers during the SC stage, MMC stage, MC stage, UM stage, BM stage, and in YP and YL of a CMS-WA line ZS97A. The mitochondrial gene ATP6 was used as an internal control, and WA352 transcript levels are shown relative to ATP6. Data are shown as means ± SD (n = 3). (B) Immunoblot of WA352 protein in different tissues and anther developmental stages of ZS97A. The mitochondrial protein COXⅡ was used as an internal control for loading, and stages are the same as in (A). (C) Structure of full-length and truncated forms of WA352 as predicted by AlphaFold2, showing an N-terminal transmembrane domain (amino acids 1 to 150, WA3521–150) and C-terminal conserved region (amino acids 151 to 352, WA352151–352). Amino acids are colored based on their per-residue confidence scores. (D) WA352 transmembrane domains predicted using TMHMM2.0. The three-transmembrane helical domain at the N terminus is shown in purple. (E) Mitochondria protein samples from anthers at the MMC stage were separated into soluble supernatant and membrane fractions and used to analyze the localization of WA352 by immunoblotting. COXⅡ was used as a control mitochondrial membrane protein, and IDH was used as a control soluble matrix protein. (F) WA352 localizes to the inner mitochondrial membrane. Mitochondrial fractions treated with (+) or without (−) the membrane-dissolving reagent Triton X-100 and the protein-digesting enzyme proteinase K. COXⅡ was used as an inner membrane protein control, and VDAC was used as an outer membrane protein control.
Expression profiling and structural analysis of the CMS protein WA352.
(A) The mitochondrial gene WA352 is constitutively expressed in anthers during the SC stage, MMC stage, MC stage, UM stage, BM stage, and in YP and YL of a CMS-WA line ZS97A. The mitochondrial gene ATP6 was used as an internal control, and WA352 transcript levels are shown relative to ATP6. Data are shown as means ± SD (n = 3). (B) Immunoblot of WA352 protein in different tissues and anther developmental stages of ZS97A. The mitochondrial protein COXⅡ was used as an internal control for loading, and stages are the same as in (A). (C) Structure of full-length and truncated forms of WA352 as predicted by AlphaFold2, showing an N-terminal transmembrane domain (amino acids 1 to 150, WA3521–150) and C-terminal conserved region (amino acids 151 to 352, WA352151–352). Amino acids are colored based on their per-residue confidence scores. (D) WA352 transmembrane domains predicted using TMHMM2.0. The three-transmembrane helical domain at the N terminus is shown in purple. (E) Mitochondria protein samples from anthers at the MMC stage were separated into soluble supernatant and membrane fractions and used to analyze the localization of WA352 by immunoblotting. COXⅡ was used as a control mitochondrial membrane protein, and IDH was used as a control soluble matrix protein. (F) WA352 localizes to the inner mitochondrial membrane. Mitochondrial fractions treated with (+) or without (−) the membrane-dissolving reagent Triton X-100 and the protein-digesting enzyme proteinase K. COXⅡ was used as an inner membrane protein control, and VDAC was used as an outer membrane protein control.
