Figure. A proposed model for SlABCG45-mediated improvement of broomrape resistance and fruit yield in tomato (Image by IGDB)
Parasitic weeds of the Orobanchaceae family cause annual economic losses exceeding $10 billion and pose significant threats to global agriculture. Striga mainly targets monocot cereals such as maize, sorghum and millet, while broomrapes (Orobanche and Phelipanche spp.) are the main threats to economically important dicot crops such as tomato, sunflower, tobacco, potato, and chickpea.
As a class of carotenoid-derived plant hormones, strigolactones (SLs) are essential for several biological processes and are characterized as the rhizosphere signals of parasitic weeds and arbuscular mycorrhizal fungi. Recently, WANG Bing et al. from the team led by Prof. LI Jiayang at the Institute of Genetics and Developmental Biology (IGDB), Chinese Academy of Sciences (CAS), have discovered that a strigolactone transporter SlABCG45 plays essential roles in balancing the host resistance to parasitic weeds and fruit yield in tomato. Knockout of SlABCG45 confers broad-spectrum broomrape resistance without yield penalties, highlighting its potential for anti-parasitic crop breeding.
Management of parasitism is challenging, and very few resistance genes have been cloned and characterized in plants. To identify key genes that confer resistance to broomrapes, researchers performed a genome-wide association study using 152 tomato accessions and identified SlABCG45 as a crucial gene that mediates host resistance to Phelipanche aegyptiaca.
They found that SlABCG45 and its close homolog SlABCG44 were membrane-localized SL transporters with essential roles in exudation of SLs to the rhizosphere, transport of SLs from the roots to the shoots and mediation of broomrape seeds germination.
Interestingly, SlABCG45 and SlABCG44 exhibit functional differentiation. SlABCG45 expression was strongly responsive to phosphorus deficiency, an environmental signal that induces parasitism, SL biosynthesis and exudation, whereas SlABCG44 was weakly responsive to phosphorus deficiency. Furthermore, the SlABCG45 mutation had a relatively weak effect on fruit size, but the slabcg44 mutant produces smaller fruits.
The research team systematically evaluated the potential of SlABCG45 genome editing in broomrape resistance, and showed that knocking out SlAGCG45 confers durable and broad-spectrum resistance to broomrape species in tomato.
Importantly, field experiments over two successive years in Xinjiang Province demonstrate that knocking out SlABCG45 significantly improved tomato resistance to broomrape, resulting in a yield increase of over30% in a Phelipanche-infested field.
Finally, they proposed that crops deficient in SL biosynthesis, such as Slccd8, exhibit resistance to broomrapes. However, the agricultural application of this strategy has been hampered by the accompanying undesirable traits, including dwarfing, excessive branch numbers, smaller and fewer fruit, and reduced fruit yield. Knockout of SlABCG45 significantly improved resistance to Phelipanche and Orobanche without sacrificing fruit development, thus elevating fruit yield in a Phelipanche-infested field. These discoveries demonstrate that SlABCG45 is a promising breeding target for increasing crop yield in the fields infested with parasitic weeds.
Contact:
WANG Bing
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences
Email: bingwang@genetics.ac.cn
CAS
中文
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Figure. A proposed model for SlABCG45-mediated improvement of broomrape resistance and fruit yield in tomato (Image by IGDB)Parasitic weeds of the Orobanchaceae family cause annual economic losses exceeding $10 billion and pose significant threats to global agriculture. Striga mainly targets monocot cereals such as maize, sorghum and millet, while broomrapes (Orobanche and Phelipanche spp.) are the main threats to economically important dicot crops such as tomato, sunflower, tobacco, potato, and chickpea.As a class of carotenoid-derived plant hormones, strigolactones (SLs) are essential for several biological processes and are characterized as the rhizosphere signals of parasitic weeds and arbuscular mycorrhizal fungi. Recently, WANG Bing et al. from the team led by Prof. LI Jiayang at the Institute of Genetics and Developmental Biology (IGDB), Chinese Academy of Sciences (CAS), have discovered that a strigolactone transporter SlABCG45 plays essential roles in balancing the host resistance to parasitic weeds and fruit yield in tomato. Knockout of SlABCG45 confers broad-spectrum broomrape resistance without yield penalties, highlighting its potential for anti-parasitic crop breeding.The study was published online in The Innovation on January 28, 2025 (DOI: 10.1016/j.xinn.2025.100815).Management of parasitism is challenging, and very few resistance genes have been cloned and characterized in plants. To identify key genes that confer resistance to broomrapes, researchers performed a genome-wide association study using 152 tomato accessions and identified SlABCG45 as a crucial gene that mediates host resistance to Phelipanche aegyptiaca.They found that SlABCG45 and its close homolog SlABCG44 were membrane-localized SL transporters with essential roles in exudation of SLs to the rhizosphere, transport of SLs from the roots to the shoots and mediation of broomrape seeds germination.Interestingly, SlABCG45 and SlABCG44 exhibit functional differentiation. SlABCG45 expression was strongly responsive to phosphorus deficiency, an environmental signal that induces parasitism, SL biosynthesis and exudation, whereas SlABCG44 was weakly responsive to phosphorus deficiency. Furthermore, the SlABCG45 mutation had a relatively weak effect on fruit size, but the slabcg44 mutant produces smaller fruits.The research team systematically evaluated the potential of SlABCG45 genome editing in broomrape resistance, and showed that knocking out SlAGCG45 confers durable and broad-spectrum resistance to broomrape species in tomato.Importantly, field experiments over two successive years in Xinjiang Province demonstrate that knocking out SlABCG45 significantly improved tomato resistance to broomrape, resulting in a yield increase of over30% in a Phelipanche-infested field.Finally, they proposed that crops deficient in SL biosynthesis, such as Slccd8, exhibit resistance to broomrapes. However, the agricultural application of this strategy has been hampered by the accompanying undesirable traits, including dwarfing, excessive branch numbers, smaller and fewer fruit, and reduced fruit yield. Knockout of SlABCG45 significantly improved resistance to Phelipanche and Orobanche without sacrificing fruit development, thus elevating fruit yield in a Phelipanche-infested field. These discoveries demonstrate that SlABCG45 is a promising breeding target for increasing crop yield in the fields infested with parasitic weeds.Contact:WANG BingInstitute of Genetics and Developmental Biology, Chinese Academy of SciencesEmail: bingwang@genetics.ac.cn