科研之友
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摘要
Stem elongation can be suppressed by a temperature drop at the onset of the photoperiod (DROP) or with a cooler day than night temperature (DT and NT, respectively), commonly described as DIF (DT - NT). To test our hypothesis that phytochrome A (phyA) mediated the reduction of stem elongation caused by - DIF and DROP, we conducted experiments with photomorphogenic mutants of tomato (Solanum lycopersicon L.) and transgenic potato (Solanum tuberosum L.). The plants studied were tomato mutants fri(1) (deficient in phyA) and tri(3) (deficient in phytochrome B1 [phyB1]) and their isogenic wild-type (WT) cv. Moneymaker, nontransformed potato, and two lines each of antisense phyA (15-9 and 15-11) and overexpressed phyA (PS-2 and PS-4). Plants were placed in three temperature regimens with a daily mean of 20 degrees C: a constant 20 degrees C (0 DIF), an 8 degrees C DROP for 3 h, and a -8 degrees C DIF. For all tomato genotypes, -DIF and DROP reduced internode length by greater than or equal to 21% and stem elongation by 30% compared to that of plants at 0 DIF. Interactions between temperature treatment and genotype were nonsignificant. For potato, - DIF, but not DROP, significantly reduced internode length of WT (by 39%) and both antisense lines (by 36 or 48%) but only one of the two lines of overexpressed phyA plants (by 18%). The - DIF significantly reduced stem length for only antisense phyA (by 36 or 48%) and WT (by 35%) plants. Thus, at least for tomato and potato. it appears that phyA does not control stem extension in relation to cool-temperature treatments.
- 出版日期1998-12
