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| Titel |
The physiology mechanisms on drought tolerance and adaptation of biological soil crust moss Bryum argenteum and Didymodon vinealis in Tenger Desert |
| VerfasserIn |
X. Zhao., Y. Shi., C. Chen, R. Jia., X. Li. |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250060223
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| Zusammenfassung |
| Bryum argenteum Hedw. and Didymodon vinealis Brid are two dominant moss species in the
restored vegetation area in Tenger Desert, which sampled from biological soil crusts and
where is an extreme drought regions. We found that they resorted to different osmotic
adjustment strategies to mitigate osmotic stress. Under the gradual drought stress, both
Bryum argenteum and Didymodon vinealis accumulated K+ and soluble sugar such as
sucrose and trehalose. Their glycine betaine contents both decreased, while their proline
content had no significant change. With enhanced drought stress, Bryum argenteum’s Na+
content was low and decreased significantly, whereas Didymodon vinealis’s Na+ content
increased sharply and reached to a high level. We found the different of the mechanism of
between active oxygen scavenging on Enzymatic and non - enzymatic system in
two species moss of Bryum argenteum Hedw and Didymodon vinealis Brid under
extreme drought stress. The result showed that two species of Moss of SOD activity
gradually enhanced, and they have the material basis for effectively eliminates in
vivo of Superoxide free radical. POD in Didymodon nigrescen and CAT in Bryum
argeneum are major resistance o oxidative stress effects. The content of GSH rise with
the stress also enhanced. The mechanism of finding Bryum argenteum Hedw and
Didymodon vinealis Brid tolerance of dehydration ability were focus on different
direction, but they are all given positive response to stress and enhance resistance. We
investigated the responses of signal transduction substances to gradual drought stress in
Didymodon vinealis and Bryum argenteum. The results suggested that: under gradual
drought stress, the activities of TP H+-ATPase and PM H+-ATPase of Didymodon
vinealis and Bryum argenteum both increased, resulting in their increase of K+
contents and turgor pressures, and triggered biosynthesis of signal transduction
substances. ABA had no obvious effect in signal transduction of Bryum argenteum and
Didymodon vinealis. NO involved in the signal transduction mechanisms of Bryum
argenteum but not in Didymodon vinealis. Ca2+ played an important role in the
signal transduction of Didymodon vinealis while it was not important in Bryum
argenteum. |
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