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Showing posts from April, 2017

Mutant Series: OPEN ALL NIGHT LONG (OPAL)

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OPEN ALL NIGHT LONG. It sounds like a coffee shop or bar or club or karaoke, something like that. Interesting enough, it's a name of one Arabidopsis thaliana mutant. 
Plants have an economic life as like as most other biological systems. It makes its own food using water, sunlight, and carbon dioxide. The process knows as photosynthesis. At the day time, it opens its gate/stomata. In the daytime, light is available and perfect time for cooking/photosynthesis for them. In the night, they just close the door/stomata to prevent water loss through transpiration. So, for plants, the following things happen generally in the case of stomata opening and closure. 

Nighttime stomatal control is important from both evolutionary and ecological perspective. But, the mechanism is not clear whether this dark response is simply a passive consequence of the absence of light stimulus, or an active process recruiting other mechanisms of stomatal closure or involving independent signaling events. 
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Mutant Series: COBRA (COB)

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In 1993, Philip Benfey published a paper in Development about four mutants which have aberrant post-embryonic root development phenotypes. Among those four root morphogenesis mutants of Arabidopsis thaliana, one is known as COBRA. Certainly, it gives us a feeling of imagining a snake. The question pops up in our mind, what's the story behind this naming? Is it based on phenotype or just a wish during naming?  

In this mutant, the root expands in an unusual manner. More precisely, it appeared that the epidermal layer had the greatest expansion. In cob, the epidermal cells were approximately 15 times larger in area than wild-type cells. The cortex and stele were expanded by 2.5 and 3.9 times respectively in this mutant. Interestingly, the aerial parts of cob were very similar to wild-type [1]. This is how the morphogenic study during genetic screening helped to find a mutant specific for root development. In the following figure, we can see the similarities between mutant root morpho…

Mutant Series: HAWAIIAN SKIRT (HWS)

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The most beautiful thing about the plant is a flower. Arabidopsis thaliana has a very small characteristic flower which eventually turns into silique to produce seeds, unfortunately, no fruits! Like any other flowers, it contains petals, sepals, carpels, stamens. During the maturation of silique, it gets rid of sepals and petals. 
A recent study from Detlef Weigel team has found one mutant defective in proper silique formation from flowers. They identified the new mutant allele which is an F-box protein and works as a suppressor of the MIM156 (miRNA target mimic 156)-induced developmental and molecular phenotypes. In this mutant plants, levels of endogenous miRNAs are increased and their mRNA targets decreased. Plants constitutively expressing the particular full-length protein simulate miRNA biogenesis mutant phenotype. In combination with such mutants, it loses its delayed floral organ abscission phenotype.  

This mutant has a very funny name. HAWAIIAN SKIRT (HWS). But, if we look at …