Current research activities in Alfred’s lab
CRISPR-Cas9/CRISPR-Cpf1: multiple plant species
To improve plant architecture of ornamental grapes, petunia, lisianthus and hops through gene editing of plant growth regulators and flowering genes. CRISPR has been demonstrated to work well on lettuce to generate variegated leaves; this technology will be translated to ornamental plant species.
We are using a temperature-inducible transposon to generate mutants that adapt Florida environment. The transposition of transposon Tam3 within Antirrhinum majus is temperature-dependent. Tam3 activity in snapdragon grown at 15°C is ~1000 folds higher than ones grown at 25°C. Seeds from M2 mutants are screened for tolerance to abiotic stresses such as drought and heat tolerance, and for desirable horticultural traits such ethylene-insensitivity. Mutant with desirable traits of interest will be subjected to transposon-tagging analysis using transposon-display.
A low temperature inducible transposon mutagenesis system in Snapdragon. (a) Flowers of wild type snapdragon displays stable magenta pigments. (b) A diagram shows an active Tam3 transposon insertion at the promoter of Pal locus to block its expression. PALLIDA encodes a dihydroflavonol-4-reductase responsible for a late step in the anthocyanin biosynthetic pathway. The insertion of an active Tam3 transposon at the PAL locus (pallidarecurrens ) caused inactivation of PAL expression and white/ivory background flower at 25°C (c). When the pallidarecurrens line is grown at an inducible temperature 15°C, the induced excision of Tam3 at PAL locus will reactivate PAL gene expression and result in a restored colorful flower (d).
Edible ornamental grape: seedless Muscadine grape
Multiple local grape germplasm is available at MREC. For example, UF previously released one edible ornamental Muscadine “Southern Home” with unique maple leaf shape it is also highly resistant to Pierce’s disease, root rot etc. We are trying to breed triploid seedless “Southern Home” through inducing tetraploid and crossing with diploids.
Nano-particle-dsRNA: multiple plant species
In collaboration with UCF, we are using nanoparticles-dsRNA to suppress ethylene production and polyphenol oxidase activity to extend vase life of fresh cut flowers and to reduce physiological disorders such as browning in fresh cut fruits and vegetables.
Genetic mapping: Lettuce
In collaboration with UC-Davis, we use a RIL mapping population (PI251246 X Armenia) to conduct QTL mapping of traits related to seed/seedling vigor. We have observed distinct responses of two parents to salinity, high temperature, far-red, PEG and darkness etc.
Effects of LED light: multiple plant species
We have purchased two programmable LED plant lighting systems with seven different wavelengths. We are currently sponsored by Eco Convergence Group to test different wavelengths of LED light on lettuce growth, nutritional quality and postharvest quality. LED lights are also applied to different ornamental plant species to examine their effects on flowering and plant architecture. Photosynthesis under different treatments will be determined using LiCOR6800. We are currently testing LED effects on accumulation of antioxidant and amino acid, reduction of postharvest browning in oyster, king oyster, bottom white mushrooms.
Host Plant Silencing: multiple plant species
We are generating lettuce and tobacco with expression of gut dsRNA and insecticidal protein to arrest reproduction of whiteflies. Regenerating plants will be limited to enclosed nurseries or indoor crop production for biological control of phloem-sucking insects.
Manipulating microRNAs and their targets to regulate plant flowering and leaf development
We are continuing projects previously developed at UC-Davis to suppress or express different miRs and their targets to study the functions in plant development and stress responses.