Induction of endodormancy in crown buds of leafy spurge (Euphorbia esula L.) implicates a role for ethylene and cross-talk between photoperiod and temperature
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Leafy spurge is a model for studying well-defined phases of dormancy in underground adventitious buds (UABs) of herbaceous perennial weeds, which is a primary factor facilitating their escape from conventional control measures. A 12-week ramp down in both temperature (27 → 10 °C) and photoperiod (16 → 8 h light) is required to induce a transition from para- to endo-dormancy in UABs of leafy spurge. To evaluate the effects of photoperiod and temperature on molecular networks of UABs during this transition, we compared global transcriptome data-sets obtained from leafy spurge exposed to a ramp down in both temperature and photoperiod (RDtp) versus a ramp down in temperature (RDt) alone. Analysis of data-sets indicated that transcript abundance for genes associated with circadian clock, photoperiodism, flowering, and hormone responses (CCA1, COP1, HY5, MAF3, MAX2) preferentially increased in endodormant UABs. Gene-set enrichment analyses also highlighted metabolic pathways involved in endodormancy induction that were associated with ethylene, auxin, flavonoids, and carbohydrate metabolism; whereas, sub-network enrichment analyses identified hubs (CCA1, CO, FRI, miR172A, EINs, DREBs) of molecular networks associated with carbohydrate metabolism, circadian clock, flowering, and stress and hormone responses. These results helped refine existing models for the transition to endodormancy in UABs of leafy spurge, which strengthened the roles of circadian clock associated genes, DREBs, COP1-HY5, carbohydrate metabolism, and involvement of hormones (ABA, ethylene, and strigolactones). We further examined the effects of ethylene by application of 1-aminocyclopropane-1-carboxylate (ACC) to paradormant plants without a ramp down treatment. New vegetative growth from UABs of ACC-treated plants resulted in a dwarfed phenotype that mimicked the growth response in RDtp-induced endodormant UABs. The results of this study provide new insights into dormancy regulation suggesting a short-photoperiod treatment provides an additive cross-talk effect with temperature signals that may impact ethylene’s effect on AP2/ERF family members.
KeywordsEndodormancy Ethylene Gene networks Molecular pathways Weed genomics
The authors wish to thank Brant B. Bigger, Cheryl A. Huckle and Wayne A. Sargent for their technical assistance during this study. The authors also thank Mark West for his help in analyzing data.
- Anderson JV, Horvath DP, Chao WS, Foley ME (2010) Bud dormancy in perennial plants: a mechanism for survival. In: Lubzens E, Cerda J, Clark M (eds) Dormancy and resistance in harsh environments. Topics in current genetics 21, Chapter 5, Hohmann S (series ed). Springer, Berlin, pp 69–90CrossRefGoogle Scholar
- Eriksson ME (2000) The role of phytochrome A and gibberellins in growth under long and short day conditions. Studies in hybrid aspen. Swedish University of Agricultural Sciences, Umea (ISSN 1401-6230)Google Scholar
- Fennell A, Hoover E (1991) Photoperiod influences growth, bud dormancy, and cold-acclimation in Vitis-Labruscana and V-Riparia. J Am Soc Hortic Sci 116:270–273Google Scholar
- Hsu CY, Adams JP, Kim H, No K, Ma C, Strauss SH, Drnevich J, Vandervelde L, Ellis JD, Rice BM, Wickett N, Gunter LE, Tuskan GA, Brunner AM, Page GP, Barakat A, Carlson JE, dePamphilis CW, Luthe DS, Yuceer C (2011) FLOWERING LOCUS T duplication coordinates reproductive and vegetative growth in perennial poplar. Proc Natl Acad Sci USA 108:10756–10761PubMedCrossRefGoogle Scholar
- Lang GA, Early JD, Martin GC, Darnell RL (1987) Endo-, para-, and eco-dormancy: physiological terminology and classification for dormancy research. Hort Sci 22:371–377Google Scholar
- Maruyama K, Takeda M, Kidokoro S, Yamada K, Sakuma Y, Urano K, Fujita M, Yoshiwara K, Matsukura S, Morishita Y, Sasaki R, Suzuki H, Saito K, Shibata D, Shinozaki K, Yamaguchi-Shinozaki K (2009) Metabolic pathways involved in cold acclimation identified by integrated analysis of metabolites and transcripts regulated by DREB1A and DREB2A. Plant Physiol 150:1972–1980PubMedCrossRefGoogle Scholar
- SAS Institute Inc (2008) SAS® 9.2, Cary, NC, USAGoogle Scholar
- Stougaard RN, Masters RA, Nissen SJ (1994) Leafy spurge (Euphorbia esula) control with imidazolinone and sulfonylurea herbicides. Weed Tech 8:494–498Google Scholar