Auxin regulates cell division and elongation of the primordial cells through its concentration and then shaped the plant architecture. Cell division and elongation form the internode of soybean and result in different...Auxin regulates cell division and elongation of the primordial cells through its concentration and then shaped the plant architecture. Cell division and elongation form the internode of soybean and result in different plant heights and lodging resistance. Yet the mechanisms behind are unclear in soybean. To elucidate the mechanism of the concentration difference of auxin related to stem development in soybean, samples of apical shoot, elongation zone, and mature zone from the developing stems of soybean seedlings, Charleston, were harvested and measured for auxin concentration distributions and metabolites to identify the common underlying mechanisms responsible for concentration difference of auxin. Distribution of indole-3-acetic acid(IAA), indole-3-butyric acid(IBA), and methylindole-3-acetic acid(Me-IAA) were determined and auxin concentration distributions were found to have a complex regulation mechanism. The concentrations of IAA and Me-IAA in apical shoot were significantly different between elongation zone and mature zone resulting in an IAA gradient. Tryptophan dependent pathway from tryptamine directly to IAA or through indole-3-acetonitrile to IAA and from indole-3-propionic acid(IPA) to IAA were three primary IAA synthesis pathways. Moreover, some plant metabolites from flavonoid and phenylpropanoid synthesis pathways showed similar or reverse gradient and should involve in auxin homeostasis and concentration difference. All the data give the first insight in the concentration difference and homeostasis of auxin in soybean seedlings and facilitate a deeper understanding of the molecular mechanism of stem development and growth. The gathered information also helps to elucidate how plant height is formed in soybean and what strategy should be adopted to regulate the lodging resistance in soybean.展开更多
Maturity period is a critical trait in soybean breeding and determines the particularly ecological region of a cultivar.In present study,118 soybean varieties spanning three artificial breeding periods(1923-1970,the e...Maturity period is a critical trait in soybean breeding and determines the particularly ecological region of a cultivar.In present study,118 soybean varieties spanning three artificial breeding periods(1923-1970,the early breeding period;1971-1990,the mid-breeding period;and 1991-2010,the current breeding period)in northeast China were selected.Fourteen DNA-specified markers including cleaved amplified polymorphic sequences(CAPS),derived CAPS(d CAPS)and fragment length polymorphism(FLP)markers were filtered to analyze the genetic diversity from E1 to E4.The results were as the followings:the soybean varieties with more gene frequencies showed more gene diversities.Among the E genes,E1 and E3 genes showed more allelic diversities than E2,and E4 only had diversity in the early breeding period.During the artificial process,some alleles of E genes disappeared and some new ones were generated.More gene diversities were observed in soybean germplasms,and new excellent germplasms could be explored to improve yield traits in artificial breeding programs.Furthermore,six different E gene combinations were observed in the early breeding period,five in the mid-breeding period and 11 in the current breeding period.Three elite genotypes were identified through a century artificial selection,while new genotypes were also found in different breeding periods.Of them,e1-nle2e3-tr E4 was a new soybean genotype of extremely early maturity in the current breeding period,which was widely suitable for planting in 00 and 000 maturity groups.Moreover,significant correlation was found between E2 and E3,suggesting that light length and light quality were two key factors for soybean maturity in northeast China.The understanding of the E genes variation underlying soybean maturity could facilitate the procession to breed elite varieties adapted for diverse regions.展开更多
基金financially supported by the National Natural Science Foundation of China(31571693)the earmarked fund for China Agriculture Research System(CARS-04-04B)。
文摘Auxin regulates cell division and elongation of the primordial cells through its concentration and then shaped the plant architecture. Cell division and elongation form the internode of soybean and result in different plant heights and lodging resistance. Yet the mechanisms behind are unclear in soybean. To elucidate the mechanism of the concentration difference of auxin related to stem development in soybean, samples of apical shoot, elongation zone, and mature zone from the developing stems of soybean seedlings, Charleston, were harvested and measured for auxin concentration distributions and metabolites to identify the common underlying mechanisms responsible for concentration difference of auxin. Distribution of indole-3-acetic acid(IAA), indole-3-butyric acid(IBA), and methylindole-3-acetic acid(Me-IAA) were determined and auxin concentration distributions were found to have a complex regulation mechanism. The concentrations of IAA and Me-IAA in apical shoot were significantly different between elongation zone and mature zone resulting in an IAA gradient. Tryptophan dependent pathway from tryptamine directly to IAA or through indole-3-acetonitrile to IAA and from indole-3-propionic acid(IPA) to IAA were three primary IAA synthesis pathways. Moreover, some plant metabolites from flavonoid and phenylpropanoid synthesis pathways showed similar or reverse gradient and should involve in auxin homeostasis and concentration difference. All the data give the first insight in the concentration difference and homeostasis of auxin in soybean seedlings and facilitate a deeper understanding of the molecular mechanism of stem development and growth. The gathered information also helps to elucidate how plant height is formed in soybean and what strategy should be adopted to regulate the lodging resistance in soybean.
基金Supported by the National Nature Scienceof China(31571693)the National Soybean Industrial Technology System(CARS-04-04B)。
文摘Maturity period is a critical trait in soybean breeding and determines the particularly ecological region of a cultivar.In present study,118 soybean varieties spanning three artificial breeding periods(1923-1970,the early breeding period;1971-1990,the mid-breeding period;and 1991-2010,the current breeding period)in northeast China were selected.Fourteen DNA-specified markers including cleaved amplified polymorphic sequences(CAPS),derived CAPS(d CAPS)and fragment length polymorphism(FLP)markers were filtered to analyze the genetic diversity from E1 to E4.The results were as the followings:the soybean varieties with more gene frequencies showed more gene diversities.Among the E genes,E1 and E3 genes showed more allelic diversities than E2,and E4 only had diversity in the early breeding period.During the artificial process,some alleles of E genes disappeared and some new ones were generated.More gene diversities were observed in soybean germplasms,and new excellent germplasms could be explored to improve yield traits in artificial breeding programs.Furthermore,six different E gene combinations were observed in the early breeding period,five in the mid-breeding period and 11 in the current breeding period.Three elite genotypes were identified through a century artificial selection,while new genotypes were also found in different breeding periods.Of them,e1-nle2e3-tr E4 was a new soybean genotype of extremely early maturity in the current breeding period,which was widely suitable for planting in 00 and 000 maturity groups.Moreover,significant correlation was found between E2 and E3,suggesting that light length and light quality were two key factors for soybean maturity in northeast China.The understanding of the E genes variation underlying soybean maturity could facilitate the procession to breed elite varieties adapted for diverse regions.
