Effects Of Weather Factors On The Realtive Contents Of Major Storage Protein Fractions And Its Subunits In Soybean Seeds, And The Molecular Mechism Of A₅A₄B₃ And A₃B₄ Subunits Content Mutations

Twenty spring and summer soybean cultivars with different protein contents were usedto explore the effects of weather factors during the whole growth period, the vegetative andreproductive grow periods on the relative contents of their major storage protein fractionsand subunits. The cultivars were grown at six sowing times, and the weather factorsincluded the accumulation temperature, the total sunshine duration, the total rainfall, therange of temperature and the average relative humidity. Based on the prophase researchresults, the stability of seven cultivars of lacking A₅A₄B₃ subunit and two of lacking A₃B₄subunit were analyzed, and further, the null mechanism was explored. The results showedthat:(1)During the whole growth period, the effects of the five weather factors on the totalprotein content of the twenty varieties and spring varieties were significant difference at0.01 or 0.05 level, but for summer cultivars no effects of the range of temperature and theaverage relative humidity on the total protein content were found.(2)During the whole growth period, the correlative coefficients between theaccumulation temperature and the total sunshine duration, and the 11S content and the11S/7S ratio of the twenty soybean were very markedly negative, and the one between theaccumulation temperature and the 11S content was positive at 0.01 level. But no effects ofthe weather factors on the 7S and I1S contents and the 11S/7S ratio of the spring andsummer soybean, respectively, were found to be significant.(3)Analyzing on different cultivars, the effects of the five weather factors on therelative contents of their major storage protein fractions and subunits of summer cultivarswere found to be not significant, but in the spring cultivars the effects on many relativecontents of the subunits were significant at 0.01 or 0.05 level; The effects of weather factorsduring the whole growth period on each subunit were found to be diversified and have nodistinct orderliness.(4)The effects of weather factors and sowing time on the A₅A₄B₃ subunit and A₃B₄subunit in each mutant cultivars were not significant, and the null subunits of the mutantcultivars are stability.(5)Seven null alleles for the Gy4 glycinin gene from the seven cultivars weresequenced and the sequences were compared with that of a functional Gy4 gene from thecultivar Nannongdahuangdou. The results showed that the null phonetype probably resultedfrom a point mutant that changed the initiation codon from ATG to ATA, and the mRNAsdid not associated with polysomes as did functional Gy4 message in the control cultivar. (6)Two null alleles for the Gy5 glycinin gene from the two cultivars were sequencedand the sequences were compared with that of a functional Gy5 gene from another cultivarNannongdahuangdou. There is no significant difference in the extrons between the mutantand normal cultivars. There are more 51bp in the first intron of Gy5 gene from the twocultivars than from the control, and this may impact the transcription and crop aftertranslation. The Gy5 mRNA from Xixiaxiaolihuang can not be detected. There is a pointmutant that changed the termination codon from TAA to CAA, and the effectivetermination codon is on the 51bp downstream of the CAA. The amino acid sequence ofA₃B₄ subunit from Heidou No. 1 has a 17-Aa tail.