Maternal environment history strongly influences progeny germination responses to post-dispersal cues

GABRIELA A AUGE; BRIANNE EDWARDS; TOSHIYUKI IMAIZUMI; LINDSAY D LEVERETT; LOGAN K BLAIR; KATHLEEN DONOHUE

Austin, TX

Congreso; Plant Biology 2016; 2016

American Society of Plant Biologists

p { margin-bottom: 0.1in; direction: ltr; color: rgb(0, 0, 0); line-height: 120%; }p.western { font-family: "Liberation Serif","Times New Roman",serif; font-size: 12pt; }p.cjk { font-family: "Droid Sans Fallback"; font-size: 12pt; }p.ctl { font-family: "FreeSans"; font-size: 12pt; }Plantsuse environmental cues to align their metabolism, growth, anddevelopment to changing seasonal conditions. For annual plants, thetiming of developmental transitions will determine the environmentexperienced by subsequent life stages. In this way, seedsintegrate pre- and post-dispersal environmental information to adjustgermination to occur under conditions that are favorable for seedlingestablishment and plant growth. The environment experienced by themother plant (pre-dispersal) is expected to be a poor predictor ofthe conditions the offspring will face during and after germinationcompared with the environment experienced directly by dispersed seeds(post-dispersal). Thus, germination responses to cues duringimbibition are predicted to be stronger than responses to those samecues if experienced before dispersal. We tested this hypothesis bygrowing Arabidopsisplants under different environmental conditions during pre-dispersalstages and studied how pre-dispersal conditions affected seedresponses to post-dispersal cues. We observed that pre-dispersaltemperature, photoperiod and light quality during seed maturationstrongly influenced the germination of the progeny. Earlier changesin temperature and photoperiod duringthe vegetative stage (vernalization or short days before bolting)also influencedgermination of the progeny, even when developing seeds themselves didnot experience those cues. Surprisingly,these effects of pre-dispersal environment often overrode the effectsof the environmental conditions experienced by seeds duringimbibition. In allcases, the long-lasting effect of the pre-dispersal environmentinduced changes in primary dormancy levels and modified the responseto the post-dispersal conditions during dormancy cycling. Certainpre-dispersal environments masked genetic variation in germinationresponses to environmental conditions experienced during imbibition,which could have profound ecological consequences for seed bank andplant community dynamics. The persistence of such environmentaleffects across generations could thereby alter evolutionary responsesto selection.