PMID- 31273277
OWN - NLM
STAT- MEDLINE
DCOM- 20201026
LR  - 20210110
IS  - 2045-2322 (Electronic)
IS  - 2045-2322 (Linking)
VI  - 9
IP  - 1
DP  - 2019 Jul 4
TI  - Mechanisms underpinning the onset of seed coat impermeability and dormancy-break 
      in Astragalus adsurgens.
PG  - 9695
LID - 10.1038/s41598-019-46158-z [doi]
LID - 9695
AB  - Impermeable seed coats, i.e. physical dormancy (PY) influence the germination 
      ecology of plants from 18 angiosperm families. Astragalus adsurgens (Fabaceae; 
      Papilinoidaae) is a perennial plant widespread in temperate regions that is 
      thought to produce both permeable and impermeable seeds. Why seeds vary in the 
      permeability of their coat, in addition to the mechanisms by which impermeable 
      seeds break dormancy, are not completely understood. However, seeds are often 
      consumed by herbivores; a phenomenon that might facilitate the germination of 
      impermeable seeds. Here, we tested whether: (1) moisture content plays a 
      significant role in the onset of seed coat impermeability (and therefore PY) at 
      similar ranges reported for species from tropical ecosystems; and (2) the 
      presence of impermeable coats offer any benefits for seed survival when consumed 
      by animals. We tested these hypotheses using A. adsurgens seeds collected from 
      Inner Mongolia, China. Freshly collected seeds with a moisture content of 9.7% 
      were permeable to water and therefore not physically dormant. However, seeds 
      became impermeable when dried below a threshold of 6.5% moisture content. 
      Treating impermeable seeds with hydrochloric acid effectively broke dormancy. 
      Scanning electron microscope (SEM) revealed that HCl treated seeds had a narrow 
      opening in the hilum and extra-hilar regions, through which water entered. Seeds 
      with impermeable coats survived significantly better than permeable seeds when 
      consumed by cows. Irrespective of coat permeability, most seeds were egested 
      between 12 and 24 h. In seeds that maintained dormancy after gut passage, this 
      was broken by additional acid scarification. Overall results suggest that: (1) 
      seed coat impermeability is induced by reduced moisture content; (2) imbibition 
      primarily occurs at the hilum and extra-hilar region; and (3) impermeable seeds 
      may benefit from endozoochory.
FAU - Jaganathan, Ganesh K
AU  - Jaganathan GK
AD  - Institute of Biothermal Technology, University of Shanghai for Science and 
      Technology, Shanghai, 200093, China. jganeshcbe@gmail.com.
FAU - Li, Jiajin
AU  - Li J
AD  - Institute of Biothermal Technology, University of Shanghai for Science and 
      Technology, Shanghai, 200093, China.
FAU - Biddick, Matthew
AU  - Biddick M
AD  - School of Biological Sciences, Victoria University of Wellington, PO Box 600, 
      Wellington, 6012, New Zealand.
FAU - Han, Kang
AU  - Han K
AD  - Institute of Biothermal Technology, University of Shanghai for Science and 
      Technology, Shanghai, 200093, China.
FAU - Song, Danping
AU  - Song D
AD  - Institute of Biothermal Technology, University of Shanghai for Science and 
      Technology, Shanghai, 200093, China.
FAU - Yang, Yashu
AU  - Yang Y
AD  - Institute of Biothermal Technology, University of Shanghai for Science and 
      Technology, Shanghai, 200093, China.
FAU - Han, Yingying
AU  - Han Y
AD  - Institute of Biothermal Technology, University of Shanghai for Science and 
      Technology, Shanghai, 200093, China.
FAU - Liu, Baolin
AU  - Liu B
AD  - Institute of Biothermal Technology, University of Shanghai for Science and 
      Technology, Shanghai, 200093, China.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20190704
PL  - England
TA  - Sci Rep
JT  - Scientific reports
JID - 101563288
RN  - 059QF0KO0R (Water)
SB  - IM
MH  - Astragalus Plant/*embryology/metabolism/ultrastructure
MH  - *Cell Membrane Permeability
MH  - China
MH  - Ecology
MH  - Ecosystem
MH  - *Germination
MH  - Microscopy, Electron, Scanning
MH  - *Plant Dormancy
MH  - Seeds/*metabolism/ultrastructure
MH  - Water/*metabolism
PMC - PMC6609697
COIS- The authors declare no competing interests.
EDAT- 2019/07/06 06:00
MHDA- 2020/10/27 06:00
PMCR- 2019/07/04
CRDT- 2019/07/06 06:00
PHST- 2018/11/13 00:00 [received]
PHST- 2019/06/24 00:00 [accepted]
PHST- 2019/07/06 06:00 [entrez]
PHST- 2019/07/06 06:00 [pubmed]
PHST- 2020/10/27 06:00 [medline]
PHST- 2019/07/04 00:00 [pmc-release]
AID - 10.1038/s41598-019-46158-z [pii]
AID - 46158 [pii]
AID - 10.1038/s41598-019-46158-z [doi]
PST - epublish
SO  - Sci Rep. 2019 Jul 4;9(1):9695. doi: 10.1038/s41598-019-46158-z.