How do plants react and adjust to drought mediated stress?
Drought resistance (DR) is one aspect in which enables plants to escape, avoid and tolerate drought stress.
The second is by regulating the action of the hormones present in the plant, in particular, one called abscisic acid (or ABA).
During drought stress, ABA moves from the roots to the leaves, helping them close the stomata in them, which allow for the entry and exit of gases (CO2, oxygen, water vapour), and reduce plant growth.
Other signalling molecules called cytokinins in the plant cells also act up, delaying premature leaf ageing and death.
The third is to control transpiration (water release from the plant to the air) by closing the stomata, reducing water loss and reducing CO2 uptake.
The fourth way is to change the growth, size, shape and branching out of the roots.
The fifth is through what is termed osmotic adjustment. Here the pressure exerted by the contents of the cell against the cell wall or membrane is maintained sufficiently tense for stiffness (and no collapse or breakdown). Botanists call this turgor (swelling).
Clearly, these five processes must be controlled and triggered by genes. Two molecules called BES1 and RD26 - play key roles in regulating plant growth under drought conditions.
BES1 is involved in the process by which certain plant steroids regulate plant growth. RD26 is active only when the plant experiences drought stress (Frenemies - characteristics of friends as well as enemies).
NASA Missions
NICER: NASA will launch the world's first mission devoted to studying rapdily spinning neutron stars.
The agency plans to launch the two-in-one Neutron Star Interior Composition Explorer, or NICER, aboard SpaceX CRS-11, a cargo resupply mission to the International Space Station to be launched aboard a Falcon 9 rocket.
Neutron stars are the remnants of massive stars that, after exhausting their nuclear fuel, exploded and collapsed into super-dense spheres about the size of New York City.
Although neutron stars emit radiation across the spectrum, observing them in the energetic X-ray band offers the greatest insights into their structure and the high-energy phenomena that they host, including starquakes, thermonuclear explosions, and the most powerful magnetic fields known in the cosmos.
Sounding Rocket: NASA is set to launch a sounding rocket which will release blue-green and red artificial clouds.
The Terrier-Improved Malemute sounding rocket will test a new deployment system that will support space studies.
Sounding rockets take their name from the nautical term "to sound," which means to take measurements. The flight of a sounding rocket is short-lived, and has a parabolic trajectory.
