Some weeds such as "Cynodon dactylon" have the ability to grow in Siberia and in the hot deserts of Arabia. What is the mechanism of adaptation? Do these plants contain adaptation genes? Can these genes be transferred "transcript" to other plants?
Like some other weeds, "Cynodon dactylon" can be found growing under very diverse climatic conditions, and you asked for mechanisms of "adaptability".
You got several answers pointing diverse traits that can help a plant to survive in harsh dry and hot climates : C4 and CAM photosyntic physiology, accumulation of organic osmotica, particular fungal symbionts, thick or dense leaves, high concentrations of oils...
Ways of adaptation to stressing conditions are multiple. Each species, each individual displays a specific combination of more or less well adapted traits. Natural selection (and chance) act to retain only some combinations.
Phenotypic plasticity (the ability to change the phenotype in response to changes in the environment) is one of the traits that can be selected, and that can help a species to be "highly adaptable". But it may not be the only way. For instance, seed dormancy offers the ability to survive long periods that are incompatible with vegetative growth (not matter if it is because ot heat or of cold).
What is the mechanism of adaptation?
-- some mechanisms are knwon, some are still unknwon, and facing a new plant, you can not know a priori which mechanisms this particular species has got.
Do these plants contain adaptation genes?
-- of course adaptation is largely due to genes, and to the gene / environment interaction. BUT these genes are not the same in the various species.
Can these genes be transferred "transcript" to other plants?
-- for some of them it may be possible, but their identification will take some time, and you are never sure that the transfer of one gene to an organism with a different genetic background will have the effect that you expect.
Cold temperature and dehydration proteins are the same. For an overview see: Engineering Stress Tolerance in Cereals Using DREB/CBF Genes:
Outcomes, Problems and Perspectives
Sergiy Lopato and Peter Langridge
"dehydration-responsive element-binding proteins (DREBs), or C-repeat-binding proteins (CBFs), are among the first families of transcriptional regulators that are transcriptionally up-regulated by water deficit or low temperature1".
Hot dessert plants--look at genes for crassulassian acid metabolism (CAM), and genes for such adaptive features as fleshy/thick leaves and other adaptations to allow survival in that environment.,
Hello. The mechanism is probably multi-level and cannot be linked only to one feature, hence the root-related factors as well these of aerial parts should be considered. However, I agree that C4 photosynthesis can be one of the mechanisms allowing the plant to survive in such severe conditions. C. dactylon is one of the plants belonging to the C4-type.
See e.g. Du et al. 2011, Physiol. Plant. Differential metabolic responses of perennial grass Cynodon transvaalensis×Cynodon dactylon (C4) and Poa Pratensis (C3) to heat stress.
These kind of extemophile plants are characterized by a high level of intelligence. Yes, plants are intelligent organisms that relies on robust "memory" used to face different stress situations. They do exhibit sophisticated forms of behavior, and are able to assess current data that can lead to an advantage at a later stage.
That is the mechanisms of stress memory that should be further investigated to understand the performance of such plants.
You have already had some good answers and there is a lot of information in the literature. Try Googling "resurrection plants" for instance. However, after looking for basic data on stomatal conductance and water potentials in plants living in conditions similar to the UAE and not finding any, I think we need a lot more field data. And that poses a problem because many of the most useful instruments cannot operate at 40-50C.
Morphological and physiological plasticity which could confer "freedom from environmental constraints" to some weedy species like Cynodon dactylon could be the reason for having such ability. This is an important characteristic which "general purpose genotype"weedy species have.
Competitiveness is also another reason. This weed is a C4 and is photosynthetically efficient plant.
Hello, For all plant behaviors the important regulator mechanism is photosynthesis which allow plant to adapt in every stressed conditions especially C4.
It might be because :
1) Plants can be invaders on a new land. In there, the clima and conditions were favoring to grow and multiply.
2) Then clima changes to the previous stage and a lot of species becomes die. But this special one call : Cynodon dactilon survive.
3) Because: An special Physiological mecanism was going: before and after:
Photosynthetic capacity and accumulation of organic osmotica such as free amino
acids and proline under saline conditions.
One important question : are Cynodon dactylon from Arabia and from Siberia idnetical ? The first step to answer can be to transplant the first in the habitat of the second and vice-versa. Evolution don not stop at the speciation, heritable disparity can be great within species too, in ecology we call it "local adaptation".
I agree also that C4 photosynthesis can be one of the mechanisms allowing the plant to survive in such severe conditions, because crassulassian acid metabolism (CAM) is responsible for the survival of the monocotyledonous plant.
Thick or dense leaves and stems with higher concentrations of oils than plants in more humid zones
The use of the word "adaptable " is here a bit confuse. I use adaptation only for describing the result of the dyad variation/selection.
Like some other weeds, "Cynodon dactylon" can be found growing under very diverse climatic conditions, and you asked for mechanisms of "adaptability".
You got several answers pointing diverse traits that can help a plant to survive in harsh dry and hot climates : C4 and CAM photosyntic physiology, accumulation of organic osmotica, particular fungal symbionts, thick or dense leaves, high concentrations of oils...
Ways of adaptation to stressing conditions are multiple. Each species, each individual displays a specific combination of more or less well adapted traits. Natural selection (and chance) act to retain only some combinations.
Phenotypic plasticity (the ability to change the phenotype in response to changes in the environment) is one of the traits that can be selected, and that can help a species to be "highly adaptable". But it may not be the only way. For instance, seed dormancy offers the ability to survive long periods that are incompatible with vegetative growth (not matter if it is because ot heat or of cold).
What is the mechanism of adaptation?
-- some mechanisms are knwon, some are still unknwon, and facing a new plant, you can not know a priori which mechanisms this particular species has got.
Do these plants contain adaptation genes?
-- of course adaptation is largely due to genes, and to the gene / environment interaction. BUT these genes are not the same in the various species.
Can these genes be transferred "transcript" to other plants?
-- for some of them it may be possible, but their identification will take some time, and you are never sure that the transfer of one gene to an organism with a different genetic background will have the effect that you expect.
Numerous angles already covered, for something different try chaperonins in a search engine and it will uncover things such as "Role of plant heat-shock proteins and molecular chaperones in the abiotic stress response" Wangxia Wang, Basia Vinocur, Oded Shoseyov and Arie Altman 2004
Question is of adaptability of cynodon in two different diverse climate; desert- cold & hot. The a biotic factor are first being responded at membrane level, i.e. change in permeability apart from osmoprotectants( sugers, imino acids, polyoles) . In these hot or cold condition membrane integrity may be maintained by level of saturated( normally more under hot) or unsaturated fatty acids(more under cold) tends to provide control for shift in Phase transition temperature. Subsequently more photosynthesis because of C4 or CAM type photosynthesis. Hopefully ,such plants have ability to activate their antioxidative system and certain proteins responsible for stress tolerance. There is no specific gene identified so far, which may control plant survival
under any sever climatic condition. Normally, survival characteristics of any plant are polygenic trait.
C4 Photosynthesis is not always better than C3. In fact in temperate and cold regions the C3 is winner as the extra conversion of CO2 to malate and recycling back to PEP costs energy for plant while on the other side the photo-respiration doesn't take place in lower temperatures.
Many C4 plants are capable to shift to C3 Metabolism when there is no drought and high temperature, This way they can broaden their tolerance to climate changes. This may be the case for this plant as well.
Another point is that this plant has deep roots usually in 60 cm of soil to 2 meters so it can both absorb water effectively in desert conditions and remain viable in extra cold conditions during winter dormancy.
if we are talking about living things, all must have somehow adaptation mechanism. dear Agnes and Ebrrahim indicated very briefly about those mechanisms what might be. Plasticity is a unique charachter of the plants, it works very nicely in acclimitization steps of tissue culture samples. Vegetative production is, of course, from mother plants coming from nature but it does not mean regenerant and mother plant of same species are equal. We know just they all are almost similar. Even this example needs to be clarified but how?
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