title: Integrative effect of drought and low temperature on litchi (Litchi chinensis Sonn.) floral initiation revealed by dynamic genome-wide transcriptome analysis.
abstract: Floral induction in litchi is influenced by multiple environment cues including temperature and soil water condition. In the present study, we determined that a combined treatment consisting of 14-day drought imposed prior to exposure to 35-day low temperature (T3) significantly promoted litchi flowering relative to the low temperature alone (T2), suggesting an integrative effect of drought and low temperature on litchi floral initiation. Analysis of transcriptomic changes in leaves from different treatments showed that 2,198 and 4,407 unigenes were differentially expressed in response to drought and low temperature, respectively. 1,227 of these unigenes were expressed in response to both treatments, implying an interaction of drought and low temperature on expression of genes involved in litchi floral initiation. Additionally, 932 unigenes were consistently differentially expressed during floral induction between T2 and T3 plants, which potentially accounts for the difference of flowering time. Thirty-eight transcription factors out of these 932 unigenes were identified as hub genes with central roles in regulation of litchi floral induction. The expression of litchi homologs of well-known flowering genes was also investigated, and one Flowering Locus T (FT) homolog may play a crucial role in litchi flowering in responses to drought and low temperature.
authors.affiliation: Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Jiyuan
authors.initials: J
authors.lastname: Shen
authors.affiliation: Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Qiusheng
authors.initials: Q
authors.lastname: Xiao
authors.affiliation: Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Haiji
authors.initials: H
authors.lastname: Qiu
authors.affiliation: Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Chengjie
authors.initials: C
authors.lastname: Chen
authors.affiliation: Guangdong Litchi Engineering Research Center, College of Horticulture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Houbin
authors.initials: H
authors.lastname: Chen
mesh_terms: D003080:Cold Temperature; D055864:Droughts; D005638:Fruit / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D020869:Gene Expression Profiling; D018745:Genome, Plant; D059014:High-Throughput Nucleotide Sequencing; D032125:Litchi / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017423:Sequence Analysis, RNA; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: D010940:Plant Proteins; D018749:RNA, Plant; D014157:Transcription Factors