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The early light-induced proteins (ELIPs) are postulated to act as transient pigment-binding proteins that protect the chloroplast from photodamage caused by excessive light energy. Desert mosses such as Syntrichia caninervis, that are desiccation-tolerant and homoiochlorophyllous, are often exposed to high-light conditions when both hydrated and dry ELIP transcripts are accumulated in response to dehydration. To gain further insights into ELIP gene function in the moss S. caninervis, two ELIP cDNAs cloned from S. caninervis, ScELIP1 and ScELIP2 and both sequences were used as the basis of a transcript abundance assessment in plants exposed to high-light, UV-A, UV-B, red-light, and blue-light. ScELIPs were expressed separately in an Arabidopsis ELIP mutant Atelip. Transcript abundance for ScELIPs in gametophytes respond to each of the light treatments, in similar but not in identical ways. Ectopic expression of either ScELIPs protected PSII against photoinhibition and stabilized leaf chlorophyll content and thus partially complementing the loss of AtELIP2. Ectopic expression of ScELIPs also complements the germination phenotype of the mutant and improves protection of the photosynthetic apparatus of transgenic Arabidopsis from high-light stress. Our study extends knowledge of bryophyte photoprotection and provides further insight into the molecular mechanisms related to the function of ELIPs. must thus find a balance between the requirements for efficient light harvesting and the danger of accumulating light-induced damage when light absorption exceeds the photosynthesis capacity.Bryophytes, as one of the earliest diverging lineages of the extant land plants, are believed to have faced tremendous challenges in occupying a variety of ecological niches many of which were characterized by water deficits, high-light intensities, and increased exposure to UV radiation. In meeting these challenges bryophytes have evolved an efficient photosynthetic apparatus and photoprotection mechanisms. The drought-tolerant mosses, Rhytidium rugosum and Ceratodon purpureus, have demonstrably improved photosystem II (PSII) chlorophyll fluorescence quenching when dehydrated that is hypothesized to provide a means to dissipate excess excitation energy as heat [5]. The desert moss, Pterygoneurum lamellatum, exhibits damage to the photosynthetic apparatus that directly correlates to the rate of desiccation; F v /F m values measured for gametophores dried slowly were similar to undried controls but were significantly reduced in plants dried quickly [6]. Syntrichia caninervis and Bryum argenteum, as predominant moss species of the Gobi Desert [7], rapidly reassemble thylakoid proteins during rehydration after a desiccation event, presumably as a means to recover photosynthesis and growth [8]. These mosses also quickly increase transcript abundance for genes involved in the light reactions, photorespiration, and other photosynthesis-related genes [9,10], which presumably speeds the recovery of photosynthesis and carbon assimilation [11]. In ...

Transfer processes of potentially toxic metals (PTMs) between rock-soil systems and soil risk evaluation in the Baoshan area, Yunnan province, Southwest China. Applied Geochemistry.