Relationships between Phosphatidylglycerol Molecular Species of Thylakoid Membrane Lipids and Sensitivities to Chilling‐induced Photoinhibition in Rice

Abstract

In an attempt to explore the relationships between phosphatidylglycerol (PG) molecular species of thylakoid membrane lipids and sensitivities to chilling-induced photoinhibition, PG molecular species, D1 protein, electron transport activities of thylakoid membrane and the potential quantum yield (F(v)/F(m)) in rice treated under middle and low photon flux density (PFD) at 11 degrees C were analyzed by high performance liquid chromatography, enzyme hydrolysis, gas phase chromatography (GC) and so on. Results showed that the major molecular species of PGs in rice thylakoid membrane were 18:3/16:0, 18:3/16:1(3t), 18:2/16:0, 18:2/16:1(3t), 18:1/16:0, 18:1/16:1(3t), 16:0/16:0, 16:0/16:1(3t). There were large differences in the contents of unsaturated PG molecular species such as 18:1 approximately 3/16:0 approximately 16:1(3t) and saturated PG molecular species like 16:0/16:0 approximately 16:1(3t) among japonica cv 9516 (j-9516), japonica-indica hybrid F1 j-9516/i-SY63 (ji-95SY) and indica cv Shanyou 63 (i-SY63). J-9516 containing higher contents of unsaturated PG molecular species was manifest in stable D1 protein contents under chill and tolerant to chill-induced photoinhibition. In contrast to j-9516, i-SY63 with lower contents of unsaturated PG molecular species, exhibited unstable D1 protein contents under chill and was sensitive to chill-induced photoinhibition. ji-95SY containing middle contents of unsaturated PG molecular species between those of j-9516 and i-SY63, exhibited mid extent of sensitivity to chill-induced photoinhibition. The losses in D1 protein also account for the inhibition in electron transport activity of thylakoid membrane and the observed decline in F(v)/F(m). The PG molecular species that is efficient in raising chilling-resistant capacity were those containing unsaturated fatty acids, namely, unsaturated PG molecular species. These results implied that the substrate selectivity of the glycerol-3-phosphate acyltransferase in chloroplasts towards 16:0 or 18:1 displayed greatly the difference between japonica and indica rice. It was possible to enhance the capacity of resistance to chilling-induced photoinhibition by improving or modifying the GPAT gene.

Specific roles of phosphatidylglycerols in hosts and microbes

“…a 16:1(3t)PG or palmitoyl PG16:0. Surprisingly, such a 16:1(3t) fatty acid was not abundant in any other thylakoid membrane lipid, suggesting a specific role of PG 16:1(3t) (48). Indeed, 16:1(3t) PG was shown to facilitate dimerization of photosystem II (PSII), the first protein complex in the lightdependent reactions of photosynthesis.…”

Glycerolipid analysis during desiccation and recovery of the resurrection plant Xerophyta humilis (Bak) Dur and Schinz

“…Biological membranes are essential for the optimal functioning and structural integrity of living cells but are susceptible to abiotic stresses, particularly those associated with drought and cold (Chen & Thelen, ; Hunte & Richers, ; Ruelland & Collin, ; Zhu, Zhao, Liang, Ji, & Jiao, ). Imposition of such environmental stresses affects the organization and the dynamics of membrane components, impacting on the physico‐chemical properties of membrane phospholipids (Los & Murata, ; Tasseva, de Virville, Cantrel, Moreau, & Zachowski, ; Vaultier et al, ).…”

Photoprotection as a Trait for Rice Yield Improvement: Status and Prospects

“…Rice cultivars exhibit varying degrees of susceptibility to photoinhibition and thermal dissipation that are likely to be a result of evolution across different geological regions (Jiao et al 2003 ; Kasajima et al 2011 ). In many cases tropical japonica cultivars are found to be more prone to photoinhibition (Gesch and Heilman 1999 ; Murchie et al 1999 ; Murchie et al 2002 ; Jiao et al 2003 ; Zhu et al 2008b ) and there is evidence that these differences are associated with the ability to regulate active oxygen and membrane stability (Jiao et al 1992 ; Jiao and Ji 2001 ; Zhu et al 2008a ). However there may be a wider range of metabolic and physiological factors involved in the field that compound the effect of high light (Black et al 1995 ; Chen et al 2003 ; Wang et al 2005 ) .…”