The omission of second division gene (OSD1) gene plays a fundamental role in meiosis and is associated with 2n gamete formation in Arabidopsis thaliana. The objective of this work was to unravel the mechanisms leading to 2n pollen production, and isolate and analyze the expression patterns of OSD-like (OSDL) genes in carnation (Dianthus caryophyllus). We found an absence of the second meiotic division caused the formation of 2n pollen. Three homoeologous genes were cloned and labeled as OSDLa, OSDLb, and OSDLc in a diploid carnation. The cDNAs were 1180 bp for OSDLa, 1288 bp for OSDLb, and 971 bp for OSDLc. A strong similarity was found between the amino sequences of OSDLb and OSDLc. An evident feature of OSDLs proteins is the presence of D-box and MR-tail domains; however, the GxEN/KEN-box domain, which is distinct among the other plant proteins was absent. Quantitative real time polymerase chain reaction (qRT-PCR) analysis showed that OSDL genes maintain continuous expression in buds and other tissues. OSDLa has the highest expression in buds of 1.1–1.2 cm long (stage 2), and OSDLb has a high level of expression in buds of 0.9–1.0 cm long (stage 1) and stage 2 buds and ovary tissues in three carnation cultivars. The expression level of OSDLc was highest in ovaries. These expression patterns strongly suggest that OSDLs in carnation involve male meiosis and ovary development. These findings can have potential applications in fundamental polyploidization research and plant breeding programs in carnation.
Xuhong Zhou, Xijun Mo, Yalian Jiang, Hao Zhang, Rongpei Yu, Lihua Wang, Jihua Wang and Suping Qu
Fan Li, Guoxian Wang, Rongpei Yu, Min Wu, Qinli Shan, Lifang Wu, Jiwei Ruan and Chunmei Yang
We investigated the effects of different planting seasons and gibberellic acid treatments on the growth and development of Gypsophila paniculata to explore new approaches to controlling the flowering period. Four different cultivars were selected and continually planted in July, September, and November in the low-latitude and high-altitude region of Kunming, China (25° N, 102° E). Results showed that the vegetative growth and flowering time of Gypsophila paniculata were prolonged and postponed when the planting time was delayed. Specifically, ‘My Pink’ showed 20% and 80% rosette rates when grown in autumn and winter, respectively, thus indicating that Gypsophila paniculata is sensitive to planting time. Moreover, GA3 treatment not only can significantly promote vegetative growth but also can stimulate early flowering and suppress the occurrence of rosettes during winter. This is more specific to ‘My Pink’, which showed 40% and 80% reductions in rosette rates with four and eight GA3 treatment applications, respectively. Our study showed that seasonal variations in the growth and development of Gypsophila paniculata and GA3 treatment can effectively stimulate early flowering and suppress rosettes during winter.