Do any plants exhibit hormonal changes similar to puberty?
In flowering plants (the angiosperms) there are several developmental transitions in the life of the plant. I won't list the plants, because the list includes pretty much all of them (although the magnitude in the change of developmental pace differs widely between taxa and environments).

First there is seed germination, which is controlled hormonally. Absence of germination is usually imposed by abscisic acid, whilst germination is caused at the appropriate time by gibberellic acid and ethylene (among other things; Holdsworth, Bentsink &amp; Soppe, 2008).

Next, in many herbaceous species there is a transition between a spreading growth stage (e.g. rosette growth) and the flowering stage. The 'growth spurt' here is the differentiation and elongation of the flowering stem, and then subsequently the sudden flowering of buds. The transition is also controlled hormonally, by a variety of hormones including auxin (Zhao, 2010), gibberellic acid, ethylene (Schaller, 2012), and the long anticipated, recently confirmed florigen (Choi, 2012). Ethylene and abscisic acid then play important roles in the next developmental transition when seeds and fruits are produced and dehisced.

Small RNAs are also now being revealed to play a large role in controlling the timing of developmental, but they are upstream of the hormonal changes. In particular some key miRNAs are involved in auxin-based regulation of branching, and in embryogenesis (Nodine &amp; Bartel, 2010), and RNA silencing is involved in the switch from rosette growth to flowering growth (reviewed in Poethig, 2009 and Baurle &amp; Dean 2006).




 Bäurle I, Dean C. 2006. The Timing of Developmental Transitions in Plants. Cell 125: 655–664.
 Choi CQ. 2012. A Blossoming Field of Research: How Florigen Is Transported to Create Flowers. PLoS Biol 10: e1001311.
 Holdsworth MJ, Bentsink L, Soppe WJJ. 2008. Molecular networks regulating Arabidopsis seed maturation, after-ripening, dormancy and germination. New Phytologist 179: 33–54.
 Nodine MD, Bartel DP. 2010. MicroRNAs Prevent Precocious Gene Expression and Enable Pattern Formation During Plant Embryogenesis. Genes Dev 24: 2678–2692.
 Poethig RS. 2009. Small RNAs and developmental timing in plants. Curr Opin Genet Dev 19: 374–378.
 Schaller GE. 2012. Ethylene and the regulation of plant development. BMC Biology 10: 9.
 Zhao Y. 2010. Auxin Biosynthesis and Its Role in Plant Development.