Production of genetically stable and Odontoglossum ringspot virus-free Cymbidium orchid 'New True' plants via meristem-derived protocorm-like body (PLB) subcultures.

Background: This study aimed to produce Odontoglossum ringspot virus (ORSV)-free Cymbidium orchid 'New True' plants from ORSV-infected mother plants by culturing their meristems and successively repeating subcultures of protocorm-like bodies (PLBs) derived from the meristems.

Results: Initially, ORSV was confirmed as the causative agent of viral symptoms in orchid leaves via reverse transcription-polymerase chain reaction (RT-PCR) analysis. Meristems from infected plants were cultured to generate PLBs, which in sequence were repeatedly subcultured up to four times.

Loss of ACO4 in petunia improves abiotic stress tolerance by reducing the deleterious effects of stress-induced ethylene.

To investigate the role of ethylene (ET) in abiotic stress tolerance in petunia cv. 'Mirage Rose', petunia plants in which the ET biosynthesis gene 1-aminocyclopropane-1-carboxylic acid oxidase 4 (ACO4) was knocked out (phaco4 mutants) and wild-type (WT) plants were exposed to heat and drought conditions. Loss of function of ACO4 significantly delayed leaf senescence and chlorosis under heat and drought stress by maintaining the SPAD values and the relative water content, indicating a greater stress tolerance of phaco4 mutants than that of WT plants.

Overexpression of in Improved Flower Longevity and Cadmium-Stress Tolerance by Reducing Ethylene Production in Floral and Vegetative Tissues.

The role of , which encodes the 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme, in extending flower longevity and improving tolerance to cadmium (Cd) stress was assessed using transgenic cv. 'Mirage Rose' overexpressing and wild-type (WT) plants. The overexpression of reduced ethylene production in floral tissue via suppression of ethylene-related genes and improved flower longevity, approximately 2 to 4 days longer than WT flowers.

Overexpression of acdS gene encoding 1-aminocyclopropane-1-carboxylic acid deaminase enzyme in petunia negatively affects seed germination.

Overexpression of acdS in petunia negatively affects seed germination by suppression of ethylene biosynthesis and signaling genes and induction of abscisic acid biosynthesis genes in the seeds. The acdS gene, which encodes 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, has been overexpressed in horticultural crops to improve their tolerance to abiotic stress. However, the role of acdS in the germination of crop seeds has not been investigated, despite its suppression of ethylene production.

Role of Ethylene Biosynthesis Genes in the Regulation of Salt Stress and Drought Stress Tolerance in Petunia.

Ethylene plays a critical signaling role in the abiotic stress tolerance mechanism. However, the role of ethylene in regulating abiotic stress tolerance in petunia has not been well-investigated, and the underlying molecular mechanism by which ethylene regulates abiotic stress tolerance is still unknown. Therefore, we examined the involvement of ethylene in salt and drought stress tolerance of petunia using the petunia wild type cv.