In 1956 , the Würzburg botanist Otto Ludwig Lange observe an strange phenomenon in the Mauritanian desert in West Africa : he found plants whose leaf could heat up to 56 degrees Anders Celsius . It is astonishing that leaves can withstand such heat . At the time , the prof was ineffective to say which mechanisms were responsible for preclude the leave-taking from drying out at these temperatures . More than 50 year later , the botanists Markus Riederer and Amauri Bueno from Julius - Maximilians - Universität Würzburg ( JMU ) in Bavaria , Germany , come through in bring out the secret .
To understand what the two scientist discover , one must sleep with more about the somewhat complicated structure of a industrial plant leaf . industrial plant allow for , for example , have a skin that is normally inconspicuous to the human eye . " you may see the skin in the tomato , " explains Professor Riederer , read/write head of the JMU Chair of Botany II . Bioscientists speak of the " cuticle " . It can be imagine as a very tenuous charge card enhancer . Without this foil , the folio of the works would dry out within a little time : “ the H2O permeability of a carapace is even lower than that of a plastic foil . ”
The Würzburg biologists Markus Riederer ( left ) and Amauri Bueno found out why the folio of the escort palm do not dry out out even at temperatures above 50 degrees Celsius . ( Image : Universität Würzburg )
perpetual craft - off : Open or secretive pores?The plant hide is not a uninterrupted layer that would extend over the whole leaf . It contains legion pores , called stomata , which can open and close . The plant “ prey ” through these stomata . Riederer : " it thereby uptakes the atomic number 6 dioxide the plant needs for photosynthesis . ”
The problem is that whenever the pores open to acquire atomic number 6 dioxide , body of water also evaporates . Therefore , desert plants , in special , are continually undergoing a balancing process : do they uptake carbon dioxide to grow further , or do they end the pores to retain the precious body of water ? According to Riederer , every desert plant make up one’s mind a little differently .
Colocynths are water - spendersThe industrial plant colocynth ( Citrullus colocynthis ) , also be intimate as acrimonious cucumber , a barbarian relative of the watermelon , opens its pores when uncover to hot up in rules of order to cool down down the leafage by transpiration cooling . It " sweats " so to speak . " This makes colocynth a piddle - spender , " explains the JMU prof of ecophysiology .
The flora can yield this because it has a very deep root . This enables the plant to tip body of water sources deep in the desert dirt . As Otto Ludwig Lange found out during his experiments in the desert , the colocynth handle to make its leaf up to 15 degree cool than the desert breeze .
Date palm are water - saversThe date palm behaves quite other than . The second Würzburg data-based industrial plant , like the colocynth , subsist in oases and wadi – river valley that dry up over long catamenia . " In contrast to the colocynth , it is a water - recoverer , " says Riederer .
Because the medal does not " perspire " , its leave sometimes reach exceedingly high temperatures : they can be 11 degrees Celsius above the air travel temperature . How can it be that the leaf do not dry out at these high temperatures ? This is what JMU life scientist Amauri Bueno investigated in his doctorial thesis .
high-pitched - temperature wax for survivalHis results , publish in the Journal of Experimental Botany , revolve around the wax , which is embed in the pelt of plant and ensures their low permeability to water . After encompassing laboratory test , Bueno discovered that this wax differs between the colocynth and the appointment decoration .
The date laurel wreath has a wax that can stand firm high temperatures and therefore has a much more rainproof skin than the colocynth , even at extreme temperatures . Only because of this special wax the palm can endure in the desert . If the wax had a slightly dissimilar chemical substance composition , the leaves would dry very quickly , particularly at gamy temperatures .
According to Riederer , these experiments were highly challenging because the wax embedded in the skin is very complicated from a chemical substance point of view . Not all arcanum have been revealed yet . The bioscientists still do not understand why one plant skin is more permeable for water than the other .
Interesting for flora breedingThese current finding from JMU may be of grandness for plant breeding . If one want to tame crop plants in places where is very red-hot and dry or where clime modification could make the surroundings hotter , one has to pay attention to the plant skin when look for suitable industrial plant variety . If plants with certain cuticle waxes are selected for breeding , they have a full hazard of endurance in hot locating .
informant : Universität Würzburg
