Effect of growth temperature and total non-structural carbohydrate accumulation on growth coefficient in Petunia x hybrida petals.
It is widely believed that growth coefficient [g, respiratory cost consumed for synthesis of a unit dry weight (DW)] is independent of growth temperature. However, some studies using regression analysis indicated an increase in g at high temperatures. These two conflicting conclusions may be affected by the differences in total non-structural carbohydrate (TNC) accumulation between growth temperatures. Here, we evaluated whether g is independent of growth temperature in Petunia x hybrida petal after excluding TNC from DW. We also examined changes in g during petal development. We measured amounts of carbon, nitrogen, minerals and TNC and theoretically estimated construction cost and g. The results showed that the estimated g greatly changed with age and differed between growth temperatures. The estimated g was markedly increased by excluding TNC from DW. The effect of accumulation of TNC on the estimated g was observed at later stage of petal development. At earlier stage, the estimated g depended on the N amount. These results indicate that g changes with growth temperature and suggest that TNC accumulation must be taken into account in the estimation.
Hachiya
Takushi
T
Department of Biological Sciences, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan. takushi@biol.s.u-tokyo.ac.jp
Noguchi
Ko
K
D000465:Algorithms; D050260:Carbohydrate Metabolism; D002244:Carbon / Q000378:metabolism; D035264:Flowers / Q000254:growth & development* / Q000378:metabolism; D008903:Minerals / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D032306:Petunia / Q000254:growth & development* / Q000378:metabolism; D013696:Temperature
D008903:Minerals; D002244:Carbon; D009584:Nitrogen