title: miR172b controls the transition to autotrophic development inhibited by ABA in Arabidopsis.
abstract: Seedling establishment is a critical phase in the life of plants when they are the most vulnerable to environment. Growth arrest at post-germinative stage under stress is the major adaptive strategy to help germinating seedlings to survive a spectrum of stressful conditions. ABA signaling is the key pathway to control stress-induced developmental arrest. However, mechanisms controlling the phase transition under abiotic stress are not fully understood. Here, we described miR172b as a new key regulator controlling transition of germinating seedlings from heterotrophic to autotrophic growth under osmotic stress in Arabidopsis. We showed that miR172b and its target SNZ were co-expressed during early seedling development. Expression of miR172b and SNZ was low after radicle emergence and sharply increased at the checkpoint to autotrophic development under normal conditions. Interestingly, activation of miR172b and SNZ was completely abolished by ABA and osmotic stress. miR172b overexpression and snz-1 exhibited increased sensitivity to ABA and osmotic stress during specific post-germinative stage, and resulted in higher expression of ABI3, ABI5 and downstream genes, such as Em6 and RAB18, than wild type under ABA treatment. Our results revealed that miR172b is a critical regulator specifically controlling cotyledon greening during post-germinative growth by directly targeting SNZ under ABA treatment and osmotic stress.
authors.affiliation: Key State Laboratory of Plant Cell and Chromosome Engineering, Center of Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, China.
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Zou
authors.forename: Youning
authors.initials: Y
authors.lastname: Wang
authors.forename: Lixiang
authors.initials: L
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Xia
authors.initials: X
authors.lastname: Li
mesh_terms: D000040:Abscisic Acid / Q000502:physiology*; D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018548:Cotyledon / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015536:Down-Regulation; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000502:physiology*; D009997:Osmotic Pressure; D010937:Plant Growth Regulators / Q000502:physiology*; D034622:RNA Interference; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013312:Stress, Physiological; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D035683:MicroRNAs; C543702:Mirn172 microRNA, Arabidopsis; D010937:Plant Growth Regulators; C544160:SNZ protein, Arabidopsis; D014157:Transcription Factors; D000040:Abscisic Acid