MiR169 and its target PagHAP2-6 regulated by ABA are involved in poplar cambium dormancy.
Dormancy is an effective strategy for perennial plants in temperate zones to survive the winter stress. MicroRNAs (miRNAs) have been well known as important regulators for various biological processes. In this study, we checked the expression of miR169 members in the cambium zone during dormancy and active growth in poplar and found that they had distinct expression patterns. We identified and characterized a dormancy-specific target gene of miR169, PagHAP2-6. 5' RACE assays confirmed the direct cleavage of PagHAP2-6 mRNA by miR169. The yeast functional complementation analysis showed that PagHAP2-6 was a homolog of Heme Activator Protein2 (HAP2)/Nuclear factor Y-A (NF-YA) transcription factor in poplar. qRT-PCR analysis indicated that PagHAP2-6 was highly expressed in the dormant stage, which was converse to the expression pattern of pag-miR169a, n, and r. In addition, the transcription of PagHAP2-6 was induced by exogenous abscisic acid (ABA), and both over-expression of PagHAP2-6 in Arabidopsis and transient co-expression assays in Nicotiana benthamiana indicated that PagHAP2-6 could increase the resistance to exogenous ABA. Taken together, the results suggested that miR169 and its target PagHAP2-6 regulated by ABA were involved in poplar cambium dormancy, which provided new insights into the regulatory mechanisms of tree dormancy-active growth transition.
State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.
Qi
Q
Ding
State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.
Jun
J
Zeng
State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China. Electronic address: hexq@pku.edu.cn.
Xin-Qiang
XQ
He
D000040:Abscisic Acid / Q000494:pharmacology*; D001483:Base Sequence; D058506:Cambium / Q000187:drug effects / Q000235:genetics*; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005816:Genetic Complementation Test; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D057445:Plant Dormancy / Q000187:drug effects / Q000235:genetics*; D018515:Plant Leaves / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D032107:Populus / Q000187:drug effects / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects
D035683:MicroRNAs; D010940:Plant Proteins; D000040:Abscisic Acid
ABA; Cambium; Dormancy; PagHAP2-6; miR169