Abstract
Background and aims: Our aim was to elucidate how plant tissues under a severe energy crisis cope with imposition of high NaCl, which greatly increases ion fluxes and hence energy demands. The energy requirements for ion regulation during combined salinity and anoxia were assessed to gain insights into ion transport processes in the anoxia-tolerant coleoptile of rice. • Methods: We studied the combined effects of anoxia plus 50 or 100 mM NaCl on tissue ions and growth of submerged rice (Oryza sativa) seedlings. Excised coleoptiles allowed measurements in aerated or anoxic conditions of ion net fluxes and O2 consumption or ethanol formation and by inference energy production. • Key Results: Over 80 h of anoxia, coleoptiles of submerged intact seedlings grew at 100 mM NaCl, but excised coleoptiles, with 50 mM exogenous glucose, survived only at 50 mM NaCl, possibly due to lower energy production with glucose than for intact coleoptiles with sucrose as substrate. Rates of net uptake of Na+ and Cl- by coleoptiles in anoxia were about half those in aerated solution. Ethanol formation in anoxia and O2 uptake in aerobic solution were each increased by 13-15 % at 50 mM NaCl, i.e. ATP formation was stimulated. For acclimation to 50 mM NaCl, the anoxic tissues used only 25 % of the energy that was expended by aerobic tissues. Following return of coleoptiles to aerated non-saline solution, rates of net K+ uptake recovered to those in continuously aerated solution, demonstrating there was little injury during anoxia with 50 mM NaCl. • Conclusion: Rice seedlings survive anoxia, without the coleoptile incurring significant injury, even with the additional energy demands imposed by NaCl (100 mM when intact, 50 mM when excised). Energy savings were achieved in saline anoxia by less coleoptile growth, reduced ion fluxes as compared to aerobic coleoptiles and apparent energy-economic ion transport systems.
| Original language | English |
|---|---|
| Pages (from-to) | 129-142 |
| Number of pages | 14 |
| Journal | Annals of Botany |
| Volume | 119 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2017 |
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Energetics of acclimation to NaCl by submerged, anoxic rice seedlings. / Kurniasih, Budiastuti; Greenway, Hank; Colmer, Timothy David.
In: Annals of Botany, Vol. 119, No. 1, 2017, p. 129-142.Research output: Contribution to journal › Article
TY - JOUR
T1 - Energetics of acclimation to NaCl by submerged, anoxic rice seedlings
AU - Kurniasih, Budiastuti
AU - Greenway, Hank
AU - Colmer, Timothy David
PY - 2017
Y1 - 2017
N2 - Background and aims: Our aim was to elucidate how plant tissues under a severe energy crisis cope with imposition of high NaCl, which greatly increases ion fluxes and hence energy demands. The energy requirements for ion regulation during combined salinity and anoxia were assessed to gain insights into ion transport processes in the anoxia-tolerant coleoptile of rice. • Methods: We studied the combined effects of anoxia plus 50 or 100 mM NaCl on tissue ions and growth of submerged rice (Oryza sativa) seedlings. Excised coleoptiles allowed measurements in aerated or anoxic conditions of ion net fluxes and O2 consumption or ethanol formation and by inference energy production. • Key Results: Over 80 h of anoxia, coleoptiles of submerged intact seedlings grew at 100 mM NaCl, but excised coleoptiles, with 50 mM exogenous glucose, survived only at 50 mM NaCl, possibly due to lower energy production with glucose than for intact coleoptiles with sucrose as substrate. Rates of net uptake of Na+ and Cl- by coleoptiles in anoxia were about half those in aerated solution. Ethanol formation in anoxia and O2 uptake in aerobic solution were each increased by 13-15 % at 50 mM NaCl, i.e. ATP formation was stimulated. For acclimation to 50 mM NaCl, the anoxic tissues used only 25 % of the energy that was expended by aerobic tissues. Following return of coleoptiles to aerated non-saline solution, rates of net K+ uptake recovered to those in continuously aerated solution, demonstrating there was little injury during anoxia with 50 mM NaCl. • Conclusion: Rice seedlings survive anoxia, without the coleoptile incurring significant injury, even with the additional energy demands imposed by NaCl (100 mM when intact, 50 mM when excised). Energy savings were achieved in saline anoxia by less coleoptile growth, reduced ion fluxes as compared to aerobic coleoptiles and apparent energy-economic ion transport systems.
AB - Background and aims: Our aim was to elucidate how plant tissues under a severe energy crisis cope with imposition of high NaCl, which greatly increases ion fluxes and hence energy demands. The energy requirements for ion regulation during combined salinity and anoxia were assessed to gain insights into ion transport processes in the anoxia-tolerant coleoptile of rice. • Methods: We studied the combined effects of anoxia plus 50 or 100 mM NaCl on tissue ions and growth of submerged rice (Oryza sativa) seedlings. Excised coleoptiles allowed measurements in aerated or anoxic conditions of ion net fluxes and O2 consumption or ethanol formation and by inference energy production. • Key Results: Over 80 h of anoxia, coleoptiles of submerged intact seedlings grew at 100 mM NaCl, but excised coleoptiles, with 50 mM exogenous glucose, survived only at 50 mM NaCl, possibly due to lower energy production with glucose than for intact coleoptiles with sucrose as substrate. Rates of net uptake of Na+ and Cl- by coleoptiles in anoxia were about half those in aerated solution. Ethanol formation in anoxia and O2 uptake in aerobic solution were each increased by 13-15 % at 50 mM NaCl, i.e. ATP formation was stimulated. For acclimation to 50 mM NaCl, the anoxic tissues used only 25 % of the energy that was expended by aerobic tissues. Following return of coleoptiles to aerated non-saline solution, rates of net K+ uptake recovered to those in continuously aerated solution, demonstrating there was little injury during anoxia with 50 mM NaCl. • Conclusion: Rice seedlings survive anoxia, without the coleoptile incurring significant injury, even with the additional energy demands imposed by NaCl (100 mM when intact, 50 mM when excised). Energy savings were achieved in saline anoxia by less coleoptile growth, reduced ion fluxes as compared to aerobic coleoptiles and apparent energy-economic ion transport systems.
KW - Anaerobic catabolism
KW - Anoxia plus NaCl
KW - Anoxia tolerance
KW - Coleoptile
KW - Complete submergence
KW - Energetics
KW - Energy crisis
KW - Energy efficient transport
KW - Ethanolic fermentation
KW - Germination
KW - NaCl x anoxia interaction
KW - Oryza sativa
KW - Salinity tolerance
UR - http://www.scopus.com/inward/record.url?scp=85014837061&partnerID=8YFLogxK
U2 - 10.1093/aob/mcw189
DO - 10.1093/aob/mcw189
M3 - Article
VL - 119
SP - 129
EP - 142
JO - Annals of Botany
JF - Annals of Botany
SN - 0305-7364
IS - 1
ER -