EFFECTS OF SUPERIMPOSED TEMPERATURE STRESS ON INVIVO CHLOROPHYLL FLUORESCENCE OF VIGNA-UNGUICULATA UNDER SALINE STRESS

被引：80

作者：

LARCHER, W ^{[1
]}

WAGNER, J ^{[1
]}

THAMMATHAWORN, A ^{[1
]}

机构：

[1] KHON KAEN UNIV, DEPT BIOL, KHON KAEN 40002, THAILAND

来源：

JOURNAL OF PLANT PHYSIOLOGY | 1990年 / 136卷 / 01期

关键词：

(Fv)[!sub]M[!/sub][!sup]dark[!/sup; (Fv′)[!sub]M[!/sub][!sup]light[!/sup; (q[!sub]N[!/sub])[!sub]max[!/sub; (q[!sub]N[!/sub])[!sub]S[!/sub; (q[!sub]p[!/sub])[!sub]S[!/sub; basic fluorescence; chlorophyll fluorescence; critical temperature for heat-induced fluorescence rise; decline after the peak of q[!sub]N[!/sub; F[!sub]M[!/sub; F[!sub]o[!/sub; F[!sub]p[!/sub; F[!sub]s[!/sub; fluorescence intensity at steady state; Fv; Fv′; highest value of q[!sub]N[!/sub] during induction; L-wave; level of q[!sub]N[!/sub] at steady state 8 min after start of induction; maximal fluorescence of a dark-adapted leaf; maximal variable fluorescence of a dark-adapted leaf; maximal variable fluorescence upon application of saturation pulses during induction; multiple stress monitoring; NaCl concentration in the root medium; NaCl[!sub]ext[!/sub; non-photochemical quenching coefficient; peak of the induction transient; PhAR; photochemical quenching coefficient; photosynthetically active radiation; photosystem I; II; primary electron acceptor of PS II; PS I; q[!sub]P[!/sub; QA; qN; ratio between fluorescence decrease and steady state fluorescence at saturating light; Rfd; saline; chilling; and heat resistance; slope of initial rise to the transient peak of q[!sub]N[!/sub; solute potential; steady state level of q[!sub]P[!/sub; sudden reversible undershoot of variable fluorescence after saturating light pulses; T[!sub]c[!/sub; T[!sub]f[!/sub; T[!sub]p[!/sub; temperature of heat-induced peak fluorescence; tg; α; β; tissue freezing temperature; variable fluorescence; variable fluorescence upon application of saturation pulses at any given time during induction; Vigna unguiculata; π;

D O I：

10.1016/S0176-1617(11)81621-4

中图分类号：

Q94 [植物学];

学科分类号：

071001 ;

摘要：

Cowpea [Vigna unguiculata (L.) Walp. var. IT 82 D-889] plants were exposed to a double stress whereby salinization (4–6 weeks at 100, 150 or 200 mM NaCl in the substrate) was the predisposing, and low and high temperatures were the additional constraints. Stress responses were assessed by measuring deviations from normal photosynthetic function by in vivo chlorophyll fluorescence. Salinization alone resulted in considerable changes in morphology, ion concentration and osmolality of the cellular sap of leaves, but had remarkably little effect on fluorescence characteristics at 20 °C. Decreasing and increasing temperatures caused marked changes in the fluorescence quenching kinetics and revealed that temperatures of 5–10 °C are suboptimal, and those around 40 °C, supraoptimal. In non-salinized plants, severe temperature stress at 3–6 °C and 45–50 °C was reflected by break-points in the temperature courses of the quenching coefficients at steady state, of Fv/FM, of (Fv)Mdark/(Fv′)Mlight, and of the heat-induced rise of Fo. Mild superimposed temperature stress enhanced the unfavourable effect of saline stress on the kinetics of qN, indicating an increased impairment of the photosynthetic process in response to the combined stress. With severe superimposed temperature stress, however, the salinized plants appeared to be less susceptible than the control plants, since the threshold temperatures for abrupt deviations of Fv/FM and (Fv)Mdark/(Fv′)Mlight, and for injury indicators (chilling symptoms, tissue freezing temperatures, Tc) shifted by 2–3K in the direction of the stressing temperature. We discuss possible mechanisms for these contrasting effects, i.e. the enhancement of disturbances at sub- and superoptimal temperatures but coadaptive adjustments at extreme stress temperatures. The results demonstrate the value of employing superimposed stressors for intensifying stress expression and for providing more information on interactions between environmental factor combinations as they exist in nature. © 1990, Gustav Fischer Verlag, Stuttgart. All rights reserved.

引用

页码：92 / 102

页数：11

共 66 条

[1]

[Anonymous], [No title captured]

[2] CHILLING DAMAGE TO PHOTOSYNTHESIS IN YOUNG ZEA-MAYS .2. PHOTOCHEMICAL FUNCTION OF THYLAKOIDS INVIVO [J].