Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** crispr is a powerful tool for…

Awards issued prior to january 20, 2025, were funded under previous administrations and may not reflect the priorities and policies of the current administration.** crispr is a powerful tool for breeding new HLB-resistant citrus varieties, but has to be preceded by identifying specific gene-editing targets. Previous nifa funded research identified clas effector proteins and interacting citrus genes, however no research has been performed on editing multiple of these discovered target genes simultaneously to develop fully-HLB-resistant varieties.soilcea has previously edited three genes individually that have shown improved resistance or tolerance to HLB. Given HLB's complex disease pathway, we will multiplex edit these three identified and proven HLB susceptibility genes simultaneously to develop new varieties with more durable resistance. For some varieties, we will also edit a gene for canker resistance. This proposal will use crispr multiplexing and protoplast transfection to target three or four previously identified and proven resistance genes simultaneously to develop non-transgenic, HLB and canker-resistant citrus varieties. This project addresses ecdre's first priority need: development of commercial citrus varieties . . . For both fresh and processed markets with genetic resistance . . . To HLB using . . . Gene editing. This project will work with sweet orange, and mandarin varieties. The first activity is multiplexed crispr-editing of three promising HLB SDE-interacting genes and one canker effector-interacting gene simultaneously, and then generation of non-transgenic, crispr-edited citrus varieties. The second activity is field trials to screen new crispr-edited varieties for disease resistance and to assess the varieties for their horticultural traitswe anticipate developing non-GMO, HLB and canker-resistant citrus trees that will be sold to growers.