Use of genetic manipulation to reduce ethylene sensitivity in ornamental plants

M. Serek
Ethylene has been known to cause many undesirable effects in a range of climacteric ornamental species. Blocking ethylene perception has been proven to be an efficient strategy to enhance the display life of flowers. One of the most effective ways to conduct such interference is through introduction of the Arabidopsis thaliana mutant gene etr1-1, which codes for an ethylene receptor. Other anti-ethylene strategies have used the PSAG12-ipt construct. To introduce the etr1-1 mutant gene or PSAG12-ipt, efficient transformation and regeneration protocols have been developed for several ethylene-sensitive ornamentals. The investigated plant species include Campanula carpatica, Kalanchoë blossfeldiana, and Petunia hybrida as well as miniature roses of Rosa hybrida and some orchid species and hybrids. The etr1-1 gene has been expressed under the control of the CaMV35S constitutive promoter from Arabidopsis thaliana or the floral-specific fbp1 promoter from Petunia. The most effective strategy was the use of fbp1::etr1-1, in which the negative influence of constitutive expression was avoided. The best transgenic T0 lines of all investigated species flowered for an extended period of time in an environment continuously ventilated with ethylene. T1 progenies showed stable inheritance and expression of etr1-1, which could be useful for future breeding purposes. Introduction of the senescence promoter PSAG12 from Arabidopsis thaliana fused with the ipt gene resulted in better ethylene resistance and higher chlorophyll content in transgenic plants compared to those of wild type. Even though genetic modification has been proven to be an effective method in preventing ethylene responses, ethylene-insensitive plants are not commercially available. Use of antibiotics for selection is a serious implication for commercial registration, especially in EU countries. New methods for genetic modification, such use of the CRISPR/Cas9 technique, should be more acceptable for commercial registration.
Serek, M. (2020). Use of genetic manipulation to reduce ethylene sensitivity in ornamental plants. Acta Hortic. 1278, 165-172
DOI: 10.17660/ActaHortic.2020.1278.25
Campanula, etr1-1, flower longevity, floral-specific promoter, fbp1, inheritance, ipt, Kalanchoë, miniature roses, orchids, SAG12

Acta Horticulturae