Curcumorpha longiflora is a perennial chasmophyte (rock fissure plant) ginger that usually grows in crevices of calcareous rocks and forms patches on the understory of limestone monsoon rainforests. The pollination ecology of C. longiflora was studied by monitoring phenology and flowering behavior, observing pollinator activity (frequency and behavior of visitors), and the quantity and quality of pollination services. We also investigated the germination of pollen grains and growth of pollen tubes after different pollination treatments to detect its breeding system. Based on the results: (1) for the first time in Zingiberaceae a new protandrous mechanism was found with a two-day flowering to avoid autogamy in this species; (2) under field conditions, all individuals of C. longiflora usually produced only one flower every other day to keep geitonogamy to a minimum; (3) germination of pollen grains and growth rates of pollen tubes under different pollination treatments were the same 4 h later after pollination, suggesting that C. longiflora is completely self-compatible; (4) among the limited visitors, Bombus sp. and Apis florae were effective pollinators, but they were active at different times and at different stages of the flower, probably receiving different rewards.
In this study, soil physicochemical properties, microbial community structure and nematode assemblages were investigated to assess the soil qualities of an in situ phosphate mine after up to 10 years of revegetation with the nurse plant Alnus nepalensis. Our results showed that A. nepalensis cultivation significantly decreased the total P concentration, suggesting the high remediation potential. Moreover, A. nepalensis improved the levels of soil-available N and K and promoted the growth of microorganisms, as suggested by the 1.45-and even 3.26-fold increase in microbial carbon (MBC) and nitrogen (MBN), respectively, after 10 years of remediation. Soil enzyme activities relating to C (β-glucosidase), N (urease) and P (acid phosphatase) were also stimulated. The sum of the indicator phospholipid fatty acids (PLFAs) and the Gram-positive and -negative bacteria also increased significantly after restoration. The nematode density increased gradually from zero in untreated soils to 2.3 g -1 of soil after 10 years of restoration, at which time the highest percentage of plant parasites was observed. Cluster analysis produced three clusters: cultivation for 0 and 1 years in cluster 1; 2, 3 and 4 years in cluster 2; and 5 and 10 years in cluster 3. These results showed that both the nutrient pools and the stability of the soil ecosystems in the revegetated soils were gradually reestablished and that the enzyme activities (β-glucosidase and urease), the microbial community (sum of PLFAs, G + : G -) and the nematode assemblage (density and plant parasite percentage) might be used as valid bioindicators for soil heath after contamination remediation.
While eukaryotic ribosomes are widely presumed to scan mRNA for the AUG codon to initiate translation in a strictly 5′–3′ movement (strictly unidirectional scanning model), other evidence has suggested that the ribosome uses small-amplitude 5′–3′ and 3′–5′ oscillations with a net 5′–3′ movement to recognize the AUG codon (Brownian ratchet scanning model). Here, we generated 13,437 yeast variants, each with an ATG triplet placed downstream (dATGs) of the annotated ATG (aATG) codon of green fluorescent protein. We found that out-of-frame dATGs could inhibit translation at the aATG, but with diminishing strength over increasing distance between aATG and dATG, undetectable beyond ∼17 nt. Computational simulations revealed that each triplet is scanned back and forth approximately ∼10 times until an AUG codon is recognized. Collectively, our findings uncover the basic process by which eukaryotic ribosomes scan for initiation codons, and how this process could shape eukaryotic genome evolution and influence cancer development.
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