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The timing of when a plant flowers during the year is crucial toits overall survival and fitness, and in crop plants it has majoraffects on the overall yield. Barley's wild ancestors and modernwinter barley varieties germinate in the autumn, but don't floweruntil after winter has finished. One stimulus that triggersflowering is the longer days that come with spring. To know how long the day is, the plant uses its built in circadianclock, with which they time a 24 hour period. Circadian clocks arefound throughout the plant and animal kingdom, and affect allmanner of processes such as when animals eat and sleep, or whenplants photosynthesize. As anyone who has suffered jet lag knows,anything that disrupts the circadian clock of an organism causesbig problems, which is why when researchers from the John InnesCentre and the Max Planck Institute sought to characterizeScandinavian barley varieties, they were surprised to find a mutantgene that knocked out the circadian clock and its functions. The research, published in the Proceedings of the National Academy of Sciences , shows that by disrupting the circadian clock Scandinavian barleyvarieties flower independently of the length of the day. This meansthat they flower much earlier than their southern counterparts andso can fit their growth cycle into the shorter growing season. Our knowledge of plant development and genetics would suggest thatthere are ways of encouraging early flowering without affecting thecircadian clock, so why was a clock mutant selected? In the UK and much of Western Europe cold winters and warm wetsummers favored the development of barleys which didn't need theperiod of overwintering and could be planted in the spring. A lateflowering mutation in another gene called Photoperiod-1 allowed barley to be planted in the spring and use the long daysof summer to build up its yield, without its growing season beingshortened by the high temperatures experienced by its ancestorsfrom the south. This gene was also identified at the John InnesCentre, which is strategically funded by the Biotechnology andBiological Sciences Research Council (BBSRC). As barley cultivation moved north this late flowering backgroundbecame unsuitable for the short growing season in Scandinavia asthe plants couldn't achieve good yields before temperaturesplunged. This was overcome by introducing a second mutation thatremoves the influence of the circadian clock, making the barleyplants insensitive to day length and allowing earlier flowering. Alternatively, the mutation may combine early flowering withadditional useful side effects such as turning off the circadiancontrol of photosynthesis. This could help Scandinavian barleyexploit the 20 hours of sunlight during the day. This physiologicalexplanation has an intriguing parallel in animals. Reindeer havesimilarly evolved to switch off their circadian clock, abandoningthe more regimented lifestyle of their antelope ancestors to beable to display more opportunistic behavior. Plant breeders and scientists now have the tools and knowledge ofgenetics to rationally design crops to be best adapted to specificregions, and this study adds to the growing wealth of genetic dataon cereal crops. Whilst the mutation identified here would beuseless for UK barleys that benefit from late flowering, it couldbe very useful for breeding varieties to take advantage of newenvironments or changing climate. Crops have a wide distributionall over the world, representing a rich source of genetic variationand adaptation, which modern plant science is now exploring to helpdevelop better crops and protect food security. I am an expert from onlytek.com, while we provides the quality product, such as Food USB Flash Drive , USB People Memory Stick Manufacturer, Customized USB Flash Drive,and more.
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