Page 147 - PC2019 Program & Proceedings

PLANT CANADA 2019

S79. Genome-wide analysis of the SPL/miR156 unit in small grain cereals
*
Tripathi, R. ; J. Singh
McGill University

The SQUAMOSA-promoter binding like(SPL) gene family encodes transcription factors that have been
shown in many species to influence plant growth and development, but information about these genes in
small grain cereals is limited. This study identified 17 SPLgenes in barley within eight distinct groups,
that are orthologs of SPLgenes described in Arabidopsis, Brachypodium,wheat, and rice. Sixteen
barley SPLsundergo alternative splicing. Seven SPLs contain a putative miR156 target site and the
transcript levels of the miR156-targeted HvSPLs (HvSPL3,13and 23) were lower in vegetative than in
reproductive phase but this was true also for some SPLgenes such as HvSPL6that were not regulated by
miR156. An antagonistic expression pattern of miR156 and miR172b during the vegetative and the
reproductive phases also signifies their apparent function in barley growth phase transition.
Characterization of a barley mir172mutant having an abnormal, indeterminate spikelet phenotype
suggests the possible feedback role of AP2/miR172 module on HvSPLgenes. Overall, our results
highlight the role of SPLgenes in different phases of the plant development in small grain
cereals.Currently, we are analyzing the available T-DNA mutants of Brachypodiumfor functional
characterization of SPLgenes. This will provide a basis to elucidate their roles in various biological
processes, which could lead to develop future generation of cereal crops.

Rajiv Tripathi (rajiv.tripathi@mcgill.ca)

S80. Influence of epiphyllous bryophytes on the water cycle in a tropical sub montane cloud forest
in Costa Rica
Fenton, N.
Université du Québec en Abitibi-Témiscamingue (UQAT)

Globally bryophytes influence carbon, nitrogen and water cycles in areas where they cover ecosystem
surfaces. Bryophytes (mosses and liverworts) are abundant in terms of both volume and species richness
in humid tropical forests, such as tropical montane cloud forests or high montane forests (TMCF). While
the role of epiphytic bryophytes (growing on branches and trunks of trees) in the water cycle of TMCF is
starting to be explored, no work has been done on the role of epiphyllic bryophytes on the water cycle. I
studied the influence of these small species on understory species on water absorption and retention in a
tropical submontane forest in Costa Rica. Epiphyll cover increased significantly with host leaf age, and
2
volume of water absorbed per cm significantly increased with epiphyll cover, reaching a maximum of
2
0.06m per cm . Preliminary results indicate that the amount of epiphyll cover does not influence the rate
of water loss, but rather the greater amount of water retained in leaves covered in epiphylls results in
evaporation back to the atmosphere over a longer period. Going forward analyses on the influence of
epiphyll community composition on water absorption and retention will help determine the importance of
epiphyll diversity vs biomass on ecosystem function.

Nicole Fenton (nicole.fenton@uqat.ca)

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