Diversity in Action Short-Film Series
The Dimensions team will be producing an enchanting and educational short-film series called Diversity in Action featuring mosses and biocrusts transitioning from desiccation dormancy. This often breath-taking spectacle of “awakening” is demonstrated in the following videos, many of which will be incorporated into the final film series. Stay tuned for more, and enjoy these!
Mosses in Motion Video Series, Part 1
Below is a video made in the Stark Lab (by undergraduate Mandy Mountain) of “Mosses in Motion” featuring a lab-controlled hydration-desiccation event recorded via time-lapse camera.
How do arid land mosses survive in dry environments? This large arid land moss cushion from Arizona (Syntrichia ruralis) will hydrate in seconds upon natural rain events, awakening from a protective dormant state called desiccation. Watch the dynamics of drying without dying (i.e. desiccation tolerance) before your own eyes in this 21 hr time lapse video recorded at UNLV by undergraduate research volunteer, Mandy Mountain and PhD student, Theresa Clark.
- Rapid Hydration: First, you’ll see the “sleeping moss” transition from a fully desiccated cushion (dry as a bone, looking dark brown and nearly dead) to fully hydrated with the addition of 5 mL of water at 5pm! Instantaneously the moss “awakens” to a bright green, metabolically active state!
- Slow Dry: Wait for it…during 5 hrs the moss is slowly losing water without perceivable morphological changes…until 10pm when the first leaves will begin to curl (the tiny, loosened stems sitting atop the cushion curl first!).
- Rapid Morphological Curling: Then, 8 hrs later…BAM! At 6 am (13 hours from initial hydration), massive leaf curling occurs as the moss assumes a protective orientation which marks the initiation of metabolic shut-down after only a small amount of water has evaporated from the plants thin leaves.
- Water continues to evaporate slowly from the plant over the next 8 hrs, evidenced by subtle contortions of the leaves wrapping tighter and tighter around their stems!
- Back to “sleep” until the next rain!
Why do the leaves curl when drying?
- Moss leaves curl back into a protective orientation that keeps sun from contacting precious photosynthetic green tissue during prolonged periods of desiccation under a hot sun, which is often the case for mosses like Syntrichia ruralis, featured here!
Below is a video with a close-up view of these leaves uncurling (by Kyle Doherty, PhD student in PI Matt Bowker’s Lab).
And what about Syntrichia caninervis? It will uncurl rapidly but the movement in the leaves is more akin to a blooming flower rather than an uncoiling rope, as you saw above. This is because the leaves only fold up vertically when dry (appressed). Hence, when hydrating, they simply fold down! Watch this video by Jenna Ekwealor.
KQED Science: These ‘Resurrection Plants’ Spring Back to Life in Seconds
In an interview with KQED, PI Brent Mishler comments on the intrigue of desiccation tolerance, “Isn’t it amazing? We humans die without water way before we completely dry out.” His doctoral student Caleb M. Caswell-levy spoke about his study ecosystem, which has a host of desiccation tolerant mosses including a species of Syntrichia that grows only on trees! The video below produced from the interview not only shows high-resolution microscopy of these epiphytic California mosses, but also features a common microorganism who calls them home: rotifers!
Read the full story here: http://ww2.kqed.org/science/2015/06/25/these-resurrection-plants-spring-back-to-life-in-seconds/