| Bromeliaceae plants,native to America,can be classified as edible and ornamental crops according to their use Aechmea fasciata is a perennial evergreen herb.After the introduction of ornamental pineapple into China,it was mainly planted in tropical and subtropical areas with relatively high temperature,and became an important tropical flower second only to orchids and red palms.Under natural conditions,the growth of ornamental pineapple is slow and the cultivation cycle is long Ethylene or ethephon is often used to induce the flowering of pineapple to meet the market demand,but the mechanism of ethylene promoting the flowering of pineapple is not clear.In this study the pure mutant strains of A.fasciata were successfully obtained by tissue culture and rapid propagation technique,and this study was based on the transcriptome data analysis of the wild type and mutant of Aechmea fasciata.AfFPF1 gene was cloned from Aechmea fasciata and its biological information,expression pattern and function were analyzed.The main results are as follows:1.The mutant of Aechmea fasciata was screened by tissue culture technology,and the combination of mutant and wild leaves was statistically analyzed,the number of mutant leaves increased.The leaf length and width ratio were smaller,and the stem edge of mutant was found to be longer and the adventitious root increased.2.Cloning and expression pattern analysis:through data analysis and PCR technology the gene was cloned.The full length of the coding region of the gene is 312 bp,which encodes a protein of 103 amino acids.Its molecular mass was predicted to be 12.066 kDa and basic isoelectric point was 9.36.Amino acid sequence analysis and phylogenetic analysis found that AfFPF1 has a close relationship with Ananas comosus.the expression level of AfFPF1 in different tissues in wild type and mutant type by qRT-PCR.qRT-PCR showed that the AfFPF1 were expressed in all tissues.The expression level was very low in stem and leaves or even not expressed.and higher in root.It is speculated that the AfFPF1 gene may affect flowering and be related to the development of root and leaves.There are many kinds of elements upstream of the starting codon,including gibberellin,salicylic acid,methyl jasmonate,drought and hypothermia,light-response elements,cell cycle and circadian rhythm elements.Ethylene(ETH)and gibberellin(GA)were selected as exogenous hormones to treated Ananas comosuso.The expression of AfFPF1 was analyzed by qRT-PCR.AfFPF1 responds to ethylene and the expression was higher in mutant.It is inferred that the transcription of AfFPF1 is regulated by ethylene,and the difference of expression mechanism that in wild type and mutant is different.After gibberellin treatment,the expression trend was same in wild type and mutant.The expression of AfFPF1 increased at first,then decreased and then increased.And AfFPF1 may be involved in plant stress process.3.Gene function analysis:Overexpression vector of AfFPF1 was constructed and transformed into wild-type Arabidopsis thaliana by the method of agrobacterium infecting inflorescence.Three positive lines,L-1,L-2 and L-8 were obtained by resistance screening and DNA and RNA identification.It was found that the bolting time of 35S::AfFPF1 Arabidopsis lines was about 6 days earlier and the flowering time was about 5 days earlier than the wild type,of which the rosette leaves were decreased.By observe found that the root system of transgenic lines become more developed.Wild type and transgenic Arabidopsis thaliana were detected by qRT-PCR.The expression of AtLFY,AtAP1,AtFT,AtFUL and AtSOC1 was up-regulated to varying degrees,but the expression of AtFLC was inhibited.That the expression of auxin response gene AtSAUR20 and ethylene synthesis gene AtASC5 were significantly up-regulated in transgenic Arabidopsis lines,and AtGA20OX1,a gene involved in gibberellin(GA)biosynthesis,was also up-regulated.These results indicated that AfFPF1 may regulate plant flowering through varieties of hormones signaling pathways. |
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