EFFECT OF CALCIUM ON ALLEVIATION OF DECREASED PHOTOSYNTHETIC ABILITY IN SALT-STRESSED MAIZE LEAVES

doi:10.17521/cjpe.2005.0042

Abstract

Abstract:

Zea mays cv. Luyu 14' was used to study the effects of Ca 2+ on stomatal conductance, net photosynthetic rates, Mehler reactions and the activities of the antioxidant enzymes, SOD and APX, under NaCl stress. Additions of 2-16 mmol·L -1 Ca 2+ suppressed stomatal conductance of maize leaves under normal growing conditions but significantly increased stomatal conductance under NaCl stress. Mehler reaction dependent electron transport rate was increased by the addition of 2-8 mmol·L -1 Ca 2+ both in controls and in the NaCl stressed maize leaves; however, the extent of the increase was greater in salt stressed maize leaves. The total electron transport rate was reduced in controls but increased in NaCl stressed maize leaves by the addition of 2-8 mmol·L -1 Ca 2+. The addition of 8 mmol·L -1 Ca 2+ significantly increased the activities of SOD and APX with the extent of the increase greater in APX than SOD. In conclusion, addition of Ca 2+ alleviated inhibition induced by NaCl stress in maize leaves, which was associated with the promotion of photosynthesis, the enhancement of Mehler reaction, and the activities of antioxidant enzymes. The enhanced Mehler reaction could not only consume excess excitation energy to avoid over reduction of the electron chain of photosynthesis but also promoted xanthophyll cycle dependent thermal dissipation by forming a transthylakoid membrane pH gradient (ΔpH) to efficiently protect maize leaves against photodamage under salt stress. Also, the active oxygen produced via the Mehler reaction was scavenged by the enhanced anti-oxidative enzymes.

Key words: Maize, Salt stress, Photosynthesis, Mehler reaction, Ca 2+

ZHANG Nai-Hua, GAO Hui-Yuan, ZOU Qi. EFFECT OF CALCIUM ON ALLEVIATION OF DECREASED PHOTOSYNTHETIC ABILITY IN SALT-STRESSED MAIZE LEAVES[J]. Chin J Plant Ecol, 2005, 29(2): 324-330.

Add to citation manager EndNote|Ris|BibTeX

URL: https://www.plant-ecology.com/EN/10.17521/cjpe.2005.0042

https://www.plant-ecology.com/EN/Y2005/V29/I2/324

Figures/Tables 5

Fig.1 Effect of 2 mmol·L-1 and 8 mmol·L-1 CaCl2 on Fv/Fm in control and 150 mmol·L-1 NaCl stressed maize leaves (Data are means±SE of four independent measurements at room temperature (25 ℃) ) A:CK B: 150 mmol·L-1 NaCl C: 2 mmol·L-1 Ca2+ D: 150 mmol·L-1NaCl+2 mmol·L-1 Ca2+ E: 8 mmol·L-1 Ca2+ F: 150 mmol·L-1 NaCl+8 mmol·L-1 Ca2+

Fig.2 Effects of different CaCl2 concentration on stomatal conductance (Gs) and net photosynthetic rate (Pn) in control (a, c) and 150 mmol·L-1 NaCl stressed (b, d) maize leaves Measurements were made in 1 000 μmol·m-2·s-1 PFD、360 μmol·mol-1 CO2 and 25 ℃. Data are means ±SE of four independent measurements

Fig.3 Effect of different CaCl2 concentration on (ETR) m (Mehler reaction dependent electron transport rate) and (ETR) t (the total electron transport rate) in control (a, c) and 150 mmol·L-1 NaCl stressed (b, d) maize leaves Measurements were made in 1 000 μmol·m-2·s-1 PFD、360 μmol·mol-1 CO2 and 25 ℃. Data are means±SE of four independent measurementsA:CK B: 2 mmol·L-1 Ca2+ C: 8 mmol·L-1 Ca2+ D: 150 mmol·L-1NaCl E: 150 mmol·L-1NaCl+2 mmol·L-1 Ca2+ F: 150 mmol·L-1 NaCl+8 mmol·L-1 Ca2+

Fig.4 Effect of different CaCl2 concentration on NPQ in control (a) and 150 mmol·L-1 NaCl stressed maize leaves under 2 000 μmol·mol -1CO2, 20%O2 (◆) and 2 000 μmol·mol -1 CO2, 2% O2 (□) Data are means ±SE of four independent measurements at room temperature (25 ℃)

Fig.5 Effect of calcium on SOD activity (a) and APX activity (b) in 150 mmol·L-1 NaCl stressed maize leaves Data are means±SE of four independent measurements at room temperature (25 ℃) A:CK B: 150 mmol·L-1 NaCl C: 150 mmol·L-1 NaCl + 8 mmol·L-1 Ca2+

References 22

[1]	Allen R (1995). Dissectionofoxidativestresstoleranceusingtransgenicplants. PlantPhysiology, 107,1049-1054.
[2]	Asada K (1994). Productionandactionofactiveoxygenspeciesinphotosynthetictissues.In:FoyerCH, MullineauPMeds.CausesofPhotooxidativeStressinPlantsandAmeliorationofDefenceSystem. CRCPress, Florida,77-104.
[3]	Biechler K, Fock H (1996). EvidenceforthecontributionoftheMehler-peroxidasereactionindissipatingexcesselectronsindrought-stressedwheat. PlantPhysiology, 112,265-272.
[4]	Bj rkman O, Demmig-Adams B (1987). PhotonyieldofO2evolutionandchlorophyllfluorescencecharacteristicsat77Kamongvascularplantsofdiverseorigins. Planta, 170,489-504. DOI URL
[5]	Cramer GR LuchliA, Polito VS (1985). DisplacementofCa2+ byNa+ fromtheplasmalemmaofrootcells. Aprimaryresponsetosaltstress?PlantPhysiology, 79,207-211.
[6]	Demmig-Adams B, Adam ⅢWW (1992). Photoprotectionandotherresponseofplanttohighlightstress. AnnualRe viewofPlantPhysiologyandPlantMolecularBiology, 43,599-626.
[7]	Dieter P (1984). Calmodulinandcalmodulin-mediatedprogressinplants. Plant, CellandEnvironment, 7,371-380.
[8]	Ehret DL, Redmann RE, Harvey BL, Cipywnyk A (1990). Salinity-inducedcalciumdeficienciesinwheatandbarley. PlantandSoil, 128,143-151.
[9]	Foyer CH, Noctor G (2000). Oxygenprocessinginphotosyn thesis:regulationandsignaling. TheNewPhytologist, 146,359-388.
[10]	Francois LE, Donovan TJ, Maas EV (1991). Calciumdefi ciencyofartichokebudsinrelationtosalinity. HortScience, 26,549-553. DOI URL
[11]	Giannopolitis GN, Ries SK (1977). SuperoxidedismutaseⅠ.Occurrenceinhigherplants. PlantPhysiology, 59,309-315.
[12]	Greenway H, Munns R (1980). Mechanismsofsalttoleranceinnon-halophytes. AnnualReviewofPlantPhysiology, 31,149-190.
[13]	Gong M, Chen SN, Song YQ, Li ZG (1997). Effectsofcalci umandcalmodulinonintrinsicheattoleranceinrelationtoantioxidantsystemsinmaizeseedlings. AustralianJournalofPlantPhysiology, 24,371-379.
[14]	Kent LM, Luchli A (1985). Germinationandseedlinggrowthofcotton:salinity-calciuminteractions. Plant, CellandEn vironment, 8,155-159.
[15]	Lu CM, Zhang JH (1998). Effectsofwaterstressonphoto synthesis, chlorophyllfluorescenceand photoinhibitioninwheatplants. AustralianJournalofPlantPhysiology, 25,883-892.
[16]	Muranaka S, Shimizu K, Kato M (2002). Ionicandosmoticeffectsofsalinityonsingle-leafphotosynthesisintwowheatcultivarswithdifferentdroughttolerance. Photosynthetica, 40,201-207. DOI URL
[17]	Nakamura YK, Tanaka E Ohta, SakataM (1990). Protec tiveeffectsofexternalCa2+ onelongationandintracellularconcentrationofK+ inintactmungbeanrootsunderhighNaClstress. PlantandCellPhysiology, 31,815-821.
[18]	Nakano Y, Asada K (1981). Hydrogenperoxideisscavengedbyascorbate-specific peroxidaseinspinachchloroplasts. PlantandCellPhysiology, 22,867-880.
[19]	Simon PM, Bonzon HG, Marme D (1984). SubchloroplasticlocalizationofNANkinaseactivity:evidenceforaCa2+, calmodulin-dependentactivityattheenvelopeandforaCa2+,calmodulin-dependentactivityinthestromaofpeachloroplasts. FEBSLetters, 159,332-338.
[20]	Weise C, Shi LB, Heber U (1998). OxygenreductionintheMehlerreactionisinsufficienttoprotectphotosystemsⅠandⅡofleavesagainst photoinactivation. PhysiologiaPlan tarum, 102,437-446.
[21]	Willmer CM, Mansfield TA (1969). Acriticalexaminationoftheuseofdetachedepidermisinstudiesofstomatalphysiolo gy. TheNewPhytologist, 68,363-375.
[22]	Xu DQ, Shen YK (1999). Lightstress:photoinhibitionofphotosynthesisinplantsundernaturalcobditions.In:Pes sarakliMed. HandbookofPlantandCropStress2ndedn. MarcelDekker, NewYork,483-497.