CROP BIOTECH UPDATE
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A weekly summary of world developments in agri-biotech for developing countries, produced by the Global Knowledge Center on Crop Biotechnology, International Service for the Acquisition of Agri-biotech Applications SEAsiaCenter (ISAAA)
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October 22, 2025
In This Week’s Issue:
News
New Breeding Technologies
• Gene-edited Indica Rice Exhibits Basmati Aroma
• Scientists Discover Tomato Gene that Boosts Resistance Against Bacterial Wilt
• Iowa State Scientists Use Gene Editing to Explore Chromosomes of Agrobacterium tumefaciens
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NEWS
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New Breeding Technologies
GENE-EDITED INDICA RICE EXHIBITS BASMATI AROMA
Scientists from Texas Tech University and partners reported the successful use of gene editing to induce basmati aroma in non-scented indica rice IR-64. Their results are published in Plant Physiology Reports.
Aroma is one of the vital traits in rice and a key determinant for pricing. Studies have revealed that rice aroma is controlled by a recessive mutation in the betaine aldehyde dehydrogenase 2 (OsBADH2) gene that results in the synthesis of 2-acetyl-1-pyrroline (2AP). However, the non-scented rice IR-64 carries a functional OsBADH2 gene, and knocking it out could induce the aroma.
The OsBADH2 gene-targeting single guide RNA was delivered into IR-64 through Agrobacterium-mediated transformation. Analysis of the rice grains confirmed induction of 2AP, but observed a reduction in yield-related characteristics. The findings of the study established the successful use of gene editing techniques to induce rice aroma.
Read the research article in Plant Physiology Reports.
Experts from Yichun University in China discovered that SlWRKY75 plays a crucial role in helping tomatoes fight bacterial wilt, a devastating disease caused by Ralstonia solanacearum. The study, published in Frontiers of Plant Science, provides new insights into how this gene enhances disease resistance, offering potential pathways for developing stronger, more resilient tomato varieties.
In this study, the researchers observed that the SlWRKY75-overexpressing tomato lines show enhanced resistance to bacterial wilt. The generated lines show improved growth, elevated activity of key antioxidant enzymes, increased jasmonic acid (JA) accumulation, and upregulation of genes involved in JA biosynthesis and signaling. Additionally, the edited lines also showed decreased levels of hydrogen peroxide (H2O2), superoxide anion (O2–), and salicylic acid (SA) and decreased expression of SA synthesis-related and signal response-related genes.
Further analysis confirmed that SlWRKY75 interacts with SlMYC2 to activate defense pathways that improve hormone signaling and antioxidant defense in tomato immunity. The study concludes that SlWRKY75 could serve as a promising target for breeding bacterial wilt-resistant tomato cultivars for future disease management strategies.
For more information, read the abstract from Frontiers of Plant Science.
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.