Cloning GmAP1 And Analyzing Its Expression Patterns During Floral Reversion Induced By Changes Of Photoperiod In Soybean Development

The experiments included in this paper are derived from a general ecological question.Based on photoperiodism,a question was asked that how plant species adapt to photoperiod and develop stereotypcially and properly?Light and temperature are two basally ecological factors. Intrincically,species(especially plant) evolution is a progress to adapt to preferential light and temperature.In china,covered widly,many cultival species are those narrow light- and temperature-adaptation species.The experimental plant is Zigongdongdou(Glycine max[L.]Merr.), which is a cultival species,characterized with late maturation,short day-induced reproduction and high sensitivity to photoperiod.Previous experiments showed that inflorescences of Zigongdongdou took on three kinds of typical phenotypes,including normal flowers under continuous short-day light(12h/d);the whole vegetative state of shoot apical meristem under continuous long-day light(16h/d) and fused phenotypes with apical-to-basal vegetative leaves,reversed flowers and normal flowers when plants were transfer from short day(enough time to induce floral initiation) to long day condition.These results suggest that correct photoperiod is necessary for successful transition of plant development stage from vegetative stage to reproductive stage;the needed photoperiod is continuous;signals maintenning floral transition is quantitative and these phenotypes caused by variable photoperiod is siminar to those of manipulating functional AP1 conferring to Arabidopsis.APETALA1 is a member of MADS-box family with conserved domains for plant development.In combination with properties of dicotyledons preferring to bases,degenerate primers were designed.Using the pair of primers,GmAPETALA1,homolog of APETALA1 in soybean was cloned. The similarity of the cDNA and protein sequence to those of APETALA1 was 45%and 56.08%respectively.RT-PCR was conducted and showed that at long-day condition, GmAPETALA1 expression level was very low and kept low level in shoot apical meristem even increasing long-day treatment;at short-day condition,the expression level increased with more short-day treatment and have a higher level in floral organs;its expression did not expand to other tissues no matter at what conditions.For more expriments,we synthesized DIG-labelled probes using different protocols and checked their synthesis efficience.The results showed that PCR-based synthesis of ssDNA had a higher efficience than transcription-based synthesis RNA probes and PCR-based synthesis dsDNA probes.