AUTHOR=Warner Samuel , O’Neill Carmel M. , Doherty Rebecca , Wells Rachel , Penfield Steven 

TITLE=Adaptation to reductions in chilling availability using variation in PLANT HOMOLOGOUS TO PARAFIBROMIN in Brassica napus

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1481282

DOI=10.3389/fpls.2024.1481282

ISSN=1664-462X

ABSTRACT=<p>Winter annual crops are sown in late summer or autumn and require chilling to promote flowering the following spring. Floral initiation begins in autumn and winter, and in winter oilseed rape (OSR), continued chilling during flower development is necessary for high yield potential. This can be a problem in areas where chilling is not guaranteed, or as a result of changing climates. Here, we used chilling disruption and low chilling to identify loci with the potential to increase chilling efficiency in winter OSR. We report that time to flowering and yield potential under low chill conditions are affected by variation at the <italic>PLANT HOMOLOGOUS TO PARAFIBROMIN</italic> gene, a component of the plant PAF1c complex. We show that increases in winter chilling given to developing flowers can improve seed yields and that loss of function of <italic>BnaPHP.A05</italic> leads to early flowering in <italic>B. rapa</italic> and <italic>B. napus</italic> and an increase in seed set where chilling is limited. Because <italic>PHP</italic> is known to specifically target the <italic>FLOWERING LOCUS C</italic> (<italic>FLC</italic>) gene in Arabidopsis, we propose that variation at <italic>PHP</italic> is useful for breeding modifications to chilling responses in polyploid crops with multiple copies of the <italic>FLC</italic> gene.</p>