Growth and development at cold-hardening temperatures. Chloroplast ultrastructure, pigment content, and composition

Abstract

Chloroplast ultrastructure, pigment content, and composition were investigated during growth of 'Puma' rye at warm and cold-hardening temperatures. Cytological characteristics of leaf mesophyll cells were altered upon growth at cold-hardening temperatures as indicated by an apparent increase in the amount of cytoplasm. Univacuolate and multivacuolate mesophyll cells were found in leaves from cold-hardened plants, but only univacuolate mesophyll cells were found in leaves from warm-grown plants. Chloroplast ultrastructure was affected by growth at low temperature as indicated by a higher frequency of smaller granal stacks. However, there was no significant difference in the number of grana per chloroplast in mesophyll cells from either warm- or cold-grown plants. Chlorophyll per plastid increased by a factor of 1.67 upon growth at cold-hardening temperatures, as did β-carotene and the xanthophylls. However, there was no significant difference in photosynthetic unit size based on P700 measurements between chloroplasts from warm- or cold-grown tissue. Analysis of freeze-fractured thylakoid membranes indicated a loss in the bimodal nature of particle size distribution on the exoplasmic fracture face and a general increase in particle size on the protoplasmic fracture face upon growth and development at cold temperatures. However, particle densities on the exoplasmic and protoplasmic fracture faces were not significantly different in thylakoids from plastids developed at either warm or cold temperatures. It is concluded that chloroplast ultrastructure and pigment content but not composition are altered upon growth and development at cold-hardening temperatures.

Low Temperature Development Induces a Specific Decrease in trans-Δ3-Hexadecenoic Acid Content which Influences LHCII Organization

“…(13) concluded that growth and development of winter rye at low temperature results in an alteration in protein-protein interactions associated with LHCII. This is consistent with previous reports which indicated that RH thylakoids exhibited a decrease in particle size on the EF fracture face ( 17), an increase in the F685/F742 but did not exhibit a concomitant increase in PSII activity at the expense of PSI activity nor any detectable change in photosynthetic unit size (11,(15)(16)(17). However, Huner et al (10,17) have also reported that no significant differences between RH and RNH thylakoids exist with respect to pigment or polypeptide composition.…”

“…This is consistent with previous reports which indicated that RH thylakoids exhibited a decrease in particle size on the EF fracture face ( 17), an increase in the F685/F742 but did not exhibit a concomitant increase in PSII activity at the expense of PSI activity nor any detectable change in photosynthetic unit size (11,(15)(16)(17). However, Huner et al (10,17) have also reported that no significant differences between RH and RNH thylakoids exist with respect to pigment or polypeptide composition. In this report, we examine the lipid and fatty acid compositions of RH and RNH thylakoids in order to determine if the observed changes in the structure and function of RH LHCII are related to alterations in thylakoid lipid composition and content.…”

Low Temperature-Induced Decrease in trans-Δ3-Hexadecenoic Acid Content Is Correlated with Freezing Tolerance in Cereals

“…It was concluded that low growth temperature modulates the assembly and supramolecular organization of rye LHCII by altering specifically the trans-16:1 content of PG. The in vitro evidence for a low temperature induced change in the organization of LHCII is supported by in situ evidence such as freeze fracture (8), 77°K fluorescence emission spectra (5, 10) as well as evidence indicating a low temperature induced decrease in the extent ofthylakoid stacking (8,10).…”

Differential Detergent Stability of the Major Light-Harvesting Complex II in Thylakoids Isolated from Monocotyledonous and Dicotyledonous Plants

“…Tremolieres et al (9,24) were the first to present evidence that the trans-16:1 content of the primary phospholipid of higher plant thylakoids, PG, is correlated with the stabilization of the oligomeric form of LHCIIb. Subsequently, Huner et al (14,16) (12,14). Furthermore, PG has been shown to be tightly and specifically associated with LHCII during purification (16).…”