4

Selaginella lepidophylla is one of only a few species of spike mosses (Selaginellaceae) that have evolved desiccation tolerance (DT) or the ability to ‘resurrect’ from an air-dried state.

Various Selaginella species including lepidophylla have been recognised for the potential therapeutic value of their anitviral, antimicrobial, or anticancer bioactivities. Widely used in traditional medicine, the authors of a recent study on the species note that little contemporary research has been undertaken.

Above, the panel of images shows a sequence of initial dry state to full rehydration and subsequent dessication. S. lepidophylla's metabolic profile was sampled over 5 stages of this cycle.

During dehydration, the microphylls curl to form a tight ball, which is an adaptive response to protect the plant against damage due to high irradiance or temperatures, or both.

Lycophytes represent a plant lineage that lies between mosses and angiosperms and thus (as the team expected) S. lepidophylla exhibited both constitutive and inducible adaptive mechanisms of DT.

S. lepidophylla exhibits an obvious predisposition for DT by expressing a majority of metabolites, such as highly abundant trehalose, sucrose, and glucose in a constitutive manner, whereas only 16.7% and 29.5% of all compounds show significant increases or decreases in abundance upon change in hydration state, respectively.

The team found many glycolysis/gluconeogenesis and TCA cycle intermediates, sugar alcohols and sugar acids were more abundant in the hydrated state. Polyols appeared to play various roles, impeding water loss as well as reabsorption during rehydration (the slower of the two processes).

Polyols might also serve as osmoprotectants in stabilizing or preventing denaturation of proteins during dehydration, in hydroxyl radical scavenging, in redox control, in reducing ROS production, and in triggering stress-adaptive gene expression.

Vanillate, a potent antioxidant, was more abundant in hydrated states. Photooxidative/oxidative damage are carefully regulated in dessication to avoid free radical damage to membranes.

Citrulline, a non-protein amino acid analog of Arg, and allantoin, a N-rich product of purine breakdown “likely serve as nitrogen reserves or attenuate ROS accumulation and cell death”, and were associated with dessication.

Several amino acid-derived secondary metabolites also appeared to play protective roles against UV-light damage including 3-(3-hydroxyphenyl) propionate and the flavonols apigenin and naringenin in all dry and partially dry states. In addition, several nitrogen-rich and γ-glutamyl amino acids that were markedly more abundant in dry or partially dry S. lepidophylla, likely play critical roles in the acquisition of DT through the scavenging of ROS via glutathione metabolism, or the remobilization of amino acids following rehydration, or both.

Yobi et al., “Metabolomic Profiling in Selaginella lepidophylla at Various Hydration States Provides New Insights into the Mechanistic Basis of Desiccation Tolerance”. Molecular Plant, vol 6 (2013)

Conference: WashingtonDC.NextGenerationPteridology.1-5Jun2015
—_000_1728EEFA12FC4C17B018386BA72FF2F1siedu_ Content-Type: text/plain; charset=”us-ascii” Content-Transfer-Encoding: quoted-printable NEXT GENERATION PTERIDOLOGY An International Conference on Lycophyte & Fern Research 13th Smithsonian Botanical Symposium 12th Symposium of the International Organization of Plant Biosystematists 1-5 June 2015 in Washington D.C. National Museum of Natural History & United States Botanic Garden http://bit.ly/1u2HO9P If you have questions, or would like to be added to the distribution list for conference-related announcements, please email: sbs@si.edu CALL FOR COLLOQUIA Each colloquium will consist of either six 30-minute or twelve 15-minute time slots and will likely include a combination of invited and contributed presentations. Topics centered on newly emerging fields, synthesizing existing areas of research, or otherwise being of broad interest will be most competitive. Colloquium organizers are expected to assemble a diverse (in terms of gender, seniority, nationality, etc.) lineup of speakers. Colloquium proposals should include: (1) the colloquium title; (2) the names and institutional affiliations of the organizers; (3) a short abstract outlining the rationale and goals of the colloquium; (4) a preference for 30-minute or 15-minute time slots; and (5) a list of proposed speakers, with institutional affiliations and focal areas (please also indicate whether or not each speaker has been contacted and is planning to attend). Proposals (PDF) should be emailed to Eric Schuettpelz (schuettpelze@si.edu), who will confirm receipt. The deadline for full consideration of colloquium proposals by the selection committee is 1 October 2014. CALL FOR WORKSHOPS Each workshop will focus on a specific topic and directly engage the participants in a particular activity. Possible formats or elements may include hands-on activities, demonstrations, tutorials, discussions. Workshops relevant to newly emerging fields, targeting understudied/neglected topics, or otherwise being of broad interest will be most competitive. Workshop proposals should include: (1) the workshop title; (2) the names and institutional affiliations of the organizers; (3) a short abstract outlining the rationale and goals of the workshop; (4) the preferred duration of the workshop; and (5) the anticipated number of participants. Proposals (PDF) should be emailed to Eric Schuettpelz (schuettpelze@si.edu), who will confirm receipt. The deadline for full consideration of workshops proposals by the selection committee is 15 October 2014. —_000_1728EEFA12FC4C17B018386BA72FF2F1siedu_ Content-Type: text/html; charset=”us-ascii” Content-ID: Content-Transfer-Encoding: quoted-printable NEXT GENERATION PTERIDOLOGY


An International Conference on Lycophyte & Fern Research

13th Smithsonian Botanical Symposium
12th Symposium of the International Organization of Plant Biosystematists

1-5 June 2015 in Washington D.C.
National Museum of Natural History & United States Botanic Garden

http://bit.ly/1u2HO9P

If you have questions, or would like to be added to the distribution list for conference-related announcements, please email: sbs@si.edu


CALL FOR COLLOQUIA

Each colloquium will consist of either six 30-minute or twelve 15-minute time slots and will likely include a combination of invited and contributed presentations. Topics centered on newly emerging fields, synthesizing existing areas of research, or otherwise being of broad interest will be most competitive. Colloquium organizers are expected to assemble a diverse (in terms of gender, seniority, nationality, etc.) lineup of speakers.

Colloquium proposals should include: (1) the colloquium title; (2) the names and institutional affiliations of the organizers; (3) a short abstract outlining the rationale and goals of the colloquium; (4) a preference for 30-minute or 15-minute time slots; and (5) a list of proposed speakers, with institutional affiliations and focal areas (please also indicate whether or not each speaker has been contacted and is planning to attend).

Proposals (PDF) should be emailed to Eric Schuettpelz (schuettpelze@si.edu), who will confirm receipt. The deadline for full consideration of colloquium proposals by the selection committee is 1 October 2014.



CALL FOR WORKSHOPS

Each workshop will focus on a specific topic and directly engage the participants in a particular activity. Possible formats or elements may include hands-on activities, demonstrations, tutorials, discussions. Workshops relevant to newly emerging fields, targeting understudied/neglected topics, or otherwise being of broad interest will be most competitive.

Workshop proposals should include: (1) the workshop title; (2) the names and institutional affiliations of the organizers; (3) a short abstract outlining the rationale and goals of the workshop; (4) the preferred duration of the workshop; and (5) the anticipated number of participants.

Proposals (PDF) should be emailed to Eric Schuettpelz (schuettpelze@si.edu), who will confirm receipt. The deadline for full consideration of workshops proposals by the selection committee is 15 October 2014.

—_000_1728EEFA12FC4C17B018386BA72FF2F1siedu

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