Figure: Assay plate of “hairy roots” that may be used to develop improved varieties of citrus and other plants. Photo Source: Texas A&M AgriLife.

Texas A&M AgriLife Research scientists, led by Professor Kranthi Mandadi, are using a new biological technology that develops and multiplies disease-resistant citrus plants using “hairy roots.” The team is developing new ways to fight fastidious pathogens in plants including the one causing citrus greening.

Fastidious plant pathogens infect citrus, tomatoes, potatoes, grapes, peppers, and other crops. These are often transmitted by insect vectors and are responsible for billions of dollars in agricultural losses. Mandadi and his team at Weslaco developed a breakthrough method to propagate fastidious bacteria responsible for citrus greening. The technology uses pathogen-infected host tissues to produce hairy roots that can serve as biological vessels for the propagation of these pathogens in the laboratory. The hairy root screening technique led to the discovery of new antimicrobial peptides and chemicals with proven efficacy in plant materials.

The researchers used Rhizobium rhizogenes to induce transgenic hairy roots from diverse citrus cultivars such as grapefruit, sweet orange, rough lemon, and citron at efficiencies of 28% to 75%. The team was able to regenerate and clone several identical, transgenic plants from a transgenic hairy root. This is more efficient and quicker than previous methods used in the past. Genetic modification of trees like citrus has been a challenge for scientists due to their slow growth and difficulties in regeneration.

For more details, read the article in AgriLife Today.

https://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=20337