The Study On Mechanisms Of Methanol Stimulation On The Growth Of Petunia

Application of exogenous methanol on a series of plants has been reported to be able to enhance their growth and yields. This has also been validated in Ornamental plants, the results show that spraying methanol can not only promote the growth of ornamental plants, but also change the flowering of model ornamental plants and to increase the number of flowering. In this study, we use ornamental plant Petunia as experimental materials, clarify the mechanism of CH3OH stimulation on the growth of the model ornamental plant at the metabolic and transcriptional levels, the main results obtained are as followsfoliar application of different concentrations of methanol solution on potted petunia plant, to provide a preliminary exploration on whether the foliar application of different concentrations of methanol exerted an influence on petunia growth phenotype. results showed that: methanol stimulated the growth of petunia. The most important index indicating the stimulatory effect of CH3OH on plant growth is reflected as an increase in biomass, which is mainly attributed to photosynthesis. To exclude the interference of microorganisms and allow the easy reproduce of the results, different concentrations of CH3OH were added to the MS agar medium to observe the effects of CH3OH on the growth and physiological characteristics of Petunia, results showed that2mM,6mM CH3OH stimulated the growth of Petunia plants but the effects displayed a decrease pattern with the elevation of CH3OH concentration, which might be due to a higher level of the oxidative damage to membranes resulted from higher concentration (6mM) of CH3OH.Analysis for the metabolic pathway of13CH3OH indicated that free13CH3OH accumulated extremely fast in Petunia plants after treated with13CH3OH. After the concentrated extract of the sample can be observed the13CH3OH was oxidized to HI3CHO and H13COOH. Under solid MS culture conditions, the best stimulatory effect on plant growth was observed in2mM CH3OH. However, the13C-metabolic flux from2mM13CH3OH was not acted as a carbon source and used by photosynthesis but flowed into Cl metabolism to yield [3-13C]Ser. part of the13C-flux from the6mM13CH3OH flowed into Cl metabolism to yield [3-13C]Ser, and the other part was used to synthesis sugars via photosynthetic Calvin cycle. This is an obvious difference in the metabolic mechanisms between the lower and higher concentration of13CH3OH metabolism.. the stimulation of6mM CH3OH on the growth of Petunia was weaker than that of2mM CH3OH treatment All these results indicated that CH5OH metabolism had no relationship with its stimulation on the growth of Petunia. The above results suggested that HCHO, HCOOH and Gly are the downstream metabolites of CH3OH metabolism in Petunia. In this study, exogenous HCHO, HCOOH and Gly exhibited very strong toxicity to Petunia. The presence of these compounds had a severe inhibition on the stimulation of CH3OH on growth of Petunia. However, their influences on the metabolism of13CH3OH were slight. These results further suggested that the stimulation of CH3OH on plant growth is independently from its metabolism. Thus, it is hypothesized that the free CH3OH absorbed by Petunia might act as a signal molecule to modulate the plant growth. The analysis for the effect of CH3OH on the metabolic profiles of NaH13CO3confirmed that the presence of CH3OH enhanced NaH13CO3assimilation to form sugars whereas the presence of HCHO and HCOOH inhibited this process.In order to study the mechanism of methanol stimulate growth of petunia at the molecular level, the forward suppression subtractive hybridization (SSH) cDNA library was constructed for Petunia under2mM CH3OH,141of methanol responsive gene of known function were identified. Gene function clustering analysis showed that protein synthesis (20%), metabolism (12.5%) and photosynthesis (8%) the proportion of related genes, analysis the library gene expression by RT-PCR. The results showed that2mM CH3OH can be significant induction of photosynthesis-related genes, protein synthesis related genes, signal transduction related genes, gene expression. These genes may be the new genetic resources for plant responses to methanol genetic engineering in the future, Protein synthesis and photosynthesis-related genes upregulated indicate that add methanol can promote the the Petunia photosynthesis and protein synthesis, which may molecular mechanism of methanol spraying promote petunia growth,the information obtained from the SSH cDNA library established an important foundation for clarification the mechanism of methanol stimulate growth in petunia at molecular level.