TY  - GEN
T1  - Novel allele elh of the UBP14 gene affects plant organ size via cell expansion in Arabidopsis thaliana.
AU  - David, Rakesh
AU  - Ng, Pei Qin
AU  - Smith, Lisa M.
AU  - Searle, Iain R.
DO  - 10.17912/micropub.biology.000401
UR  - http://beta.micropublication.org/journals/biology/micropub-biology-000401/
AB  - Plant organ size control is an essential process of plant growth and development. The regulation of plant organ size involves a complicated network of genetic, molecular interactions, as well the interplay of environmental factors (Hepworth and Lenhlard, 2014). Two elements of plant organ size development are cell proliferation, resulting in increase in cell numbers, and cell expansion, which increases the overall organ size via larger cell area occupancy. However, our understanding of the fine-tuned regulation of organ size remains incomprehensive. Here, we report a temperature-sensitive hypocotyl elongation EMS-generated mutant, hereby referred to as elongated hypocotyl under high-temperature (elh). The elongated hypocotyl phenotype is prominent when the elh seedlings are grown at high temperature, 28°C, but not under the growth temperature of 21°C (Figure 1A). As hypocotyl elongation is driven primarily by cell elongation processes (Derbyshire et al. 2007), we compared the difference of organs size between in wild type and elh plants. We observed significantly larger organ sizes in elh plants, including cotyledons, petals and seeds when compared to the control (Student’s t-test p < 0.05, Figure 1B). We further inspected the cell size and number of these three organs in wild type and elh plants. In elh, the cell sizes in cotyledons and petals were significantly larger than wild type (Student’s t-test p < 0.05, Figure 1C). We also measured the cell density and organ area of cotyledons, petals and mature dissected embryos. By extrapolating cell numbers based on organ size, we found no differences in total cell numbers in either organ (Student’s t-test p > 0.05) indicating that cell expansion rather than cell proliferation was perturbed in elh. Plastochron, leaf initiation rate, has been previously linked to cell expansion (Wang et al. 2008). We observed reduced leaf number in elh plants when compared to wild type (Student’s t-test p < 0.05, Figure 1D) and a comprehensive analysis showed that elh plants produced leaves at a slower rate than wild type plants (Student’s t-test p < 0.05, Figure 1H), suggesting that perturbing the balance between cell division and cell expansion is linked to the developmental rate at which leaves are produced.
PY  - 2021
JO  - microPublication Biology
ER  -