Insights into the historical assembly of East Asian subtropical evergreen broadleaved forests revealed by the temporal history of the tea family.

Subtropical evergreen broadleaved forests (EBLFs) inhabit large areas of East Asia. Although paleovegetation reconstructions have revealed that the subtropical EBLFs existed in Southwest China during the Miocene, the historical construction of these forests remains poorly known. Here, we used the tea family (Theaceae), a characteristic component of the subtropical EBLFs, to gain new insights into the assembly of this important biome. Using a robust phylogenetic framework of Theaceae based on plastome and nuclear ribosomal DNA sequence data, the temporal history of the family was reconstructed. Data from other characteristic components of subtropical EBLFs, including Fagaceae, Lauraceae and Magnoliaceae, were also integrated. Most of the essential elements of the subtropical EBLFs appear to have originated around the Oligocene-Miocene (O-M) boundary. However, small woody lineages (e.g. Camellia, Hartia) from Theaceae were dated to the late Miocene. Accelerated net diversification rates within Theaceae were also detected near the O-M transition period and the late Miocene. Our results suggest that two independent intensifications of the East Asian summer monsoon (EASM) around the O-M boundary and the late Miocene may have facilitated the historical assembly of the subtropical EBLFs in East Asia.

Principles of Biomedical Agriculture Applied to the Plant Family Theaceae To Identify Novel Interventions for Cancer Prevention and Control.

Plant materials from the family Theaceae have been used for over a thousand years as integral components within the food systems of many globally distributed cultures and to treat a variety of human ailments. These markedly different uses remain of considerable interest in the 21st century. This perspective draws heavily from the agricultural and biomedical literature published using plant materials from the genus Camellia. Our objective is to provide a rationale and framework for broadening the scope of investigation of genera and species within Theaceae beyond Camellia sinensis to accelerate the development of a new generation of Theaceae-based pharmaceuticals/nutraceuticals and the more general enhancement of the food supply with Theaceae-containing products that affect the development of chronic diseases such as cancer. This will require a concerted effort to systematically capitalize on the rapidly growing knowledge of germplasm resources within Theaceae using metabolomic profiling in combination with in vivo and in vitro approaches. The successful translation of this research into products that affect human health will be facilitated by recognition of the agronomic factors that are critical in making hot water infusions generically referred to as tea as well as food products containing ground leaf powders.

Molecular phylogeny of tribe Theeae (Theaceae s.s.) and its implications for generic delimitation.

Tribe Theeae, which includes some economically important and widely grown plants, such as beverage tea and a number of woody ornamentals, is the largest member of the Theaceae family. Using five genomic regions (chloroplast: atpI-H, matK, psbA5'R-ALS-11F, rbcL; nuclear: LEAFY) and 30 species representing four of the five genera in this tribe (Apterosperma, Camellia, Polyspora, and Pyrenaria s.l.), we investigated the phylogeny of Theeae and assessed the delimitation of genera in the tribe. Our results showed that Polyspora was monophyletic and the sister of the three other genera of Theeae investigated, Camellia was paraphyletic and Pyrenaria was polyphyletic. The inconsistent phylogenetic placement of some species of Theeae between the nuclear and chloroplast trees suggested widespread hybridization between Camellia and Pyrenaria, Polyspora and Parapyrenaria. These results indicate that hybridization, rather than morphological homoplasy, has confused the current classification of Theeae. In addition, the phylogenetic placement and possible allies of Laplacea are also discussed.

Genetic diversity and domestication origin of tea plant Camellia taliensis (Theaceae) as revealed by microsatellite markers.

BACKGROUND: Tea is one of the most popular beverages in the world. Many species in the Thea section of the Camellia genus can be processed for drinking and have been domesticated. However, few investigations have focused on the genetic consequence of domestication and geographic origin of landraces on tea plants using credible wild and planted populations of a single species. Here, C. taliensis provides us with a unique opportunity to explore these issues. RESULTS: Fourteen nuclear microsatellite loci were employed to determine the genetic diversity and domestication origin of C. taliensis, which were represented by 587 individuals from 25 wild, planted and recently domesticated populations. C. taliensis showed a moderate high level of overall genetic diversity. The greater reduction of genetic diversity and stronger genetic drift were detected in the wild group than in the recently domesticated group, indicating the loss of genetic diversity of wild populations due to overexploitation and habitat fragmentation. Instead of the endangered wild trees, recently domesticated individuals were used to compare with the planted trees for detecting the genetic consequence of domestication. A little and non-significant reduction in genetic diversity was found during domestication. The long life cycle, selection for leaf traits and gene flow between populations will delay the emergence of bottleneck in planted trees. Both phylogenetic and assignment analyses suggested that planted trees may have been domesticated from the adjacent central forest of western Yunnan and dispersed artificially to distant places. CONCLUSIONS: This study contributes to the knowledge about levels and distribution of genetic diversity of C. taliensis and provides new insights into genetic consequence of domestication and geographic origin of planted trees of this species. As an endemic tea source plant, wild, planted and recently domesticated C. taliensis trees should all be protected for their unique genetic characteristics, which are valuable for tea breeding.

Isolation and characterization of EST-SSR markers in Schima mertensiana (Theaceae) using pyrosequencing technology.

PREMISE OF THE STUDY: Microsatellite or simple sequence repeat (SSR) markers from expressed sequence tags (ESTs) in Schima mertensiana, an evergreen tree that is endemic to the Bonin Islands, were developed to facilitate evaluation of the species's population genetic structure. METHODS AND RESULTS: Using 149831 ESTs derived by pyrosequencing S. mertensiana complementary DNA (cDNA), 683 EST-SSRs were developed, 48 of which were tested for amplification. Thirty of the 48 showed clear amplification and detected polymorphism in sampled populations, with mean expected heterozygosity at the amplified loci ranging from 0.045 to 0.874 (average 0.545). CONCLUSIONS: The markers developed in this study can be used for future studies of the genetic structure of S. mertensiana and related species.

[Provenance difference in stable carbon isotope discrimination of Schima superba].

The difference in leaf stable carbon isotope discrimination (delta) of 18 representative Schima superba provenances was investigated based on three provenance trails located at Jian' ou of Fujian Province and Chun' an and Qingyuan of Zhejiang Province, and the geographic variation pattern and the effects of trial site and provenances growth rate were studied. Significant differences in leaf delta were observed among the provenaces, and the differences in leaf delta value between the highest and lowest provenances reached 6.9%, 3.0%, and 3.7% in 3 experimental sites, respectively. A classic latitudinal clinical variation pattern was found, because there were significant correlations between the leaf delta value and the latitude of seed sources in all the 3 sites while no significant correlations were observed between the leaf delta value and the longitude of the seed sources. The southern provenances showed higher leaf delta value than the northern provenances, indicating that the water use efficiency (WUE) was lower in southern provenances. The leaf delta value of different provenances was demonstrated to be greatly affected by the environment of trial sites. The leaf delta value increased significantly with the improvement of site environment and with the increase of annual rainfall. Significant positive correlations were observed between the leaf delta value and the growth traits including tree height, DBH, total number of lateral branches, and length of the strongest lateral branch, which indicated that the provenances with higher growth rate and denser crown had larger leaf delta value. Two and four superior provenances with high growth rate and low leaf delta value (or high WUE) were selected for Jian' ou of Fujian and Chun' an of Zhejiang, respectively.

Molecular detection and phylogenetic analysis of the catechol 1,2-dioxygenase gene from Gordonia spp.

The C12O gene (catA gene) encodes for catechol 1,2-dioxygenase, which is a key enzyme involved in the first step catalysis of the aromatic ring in the ortho-cleavage pathway. This functional gene can be used as a marker to assess the catabolic potential of bacteria in bioremediation. C12OF and C12OR primers were designed based on the conserved regions of the CatA amino acid sequence of Actinobacteria for amplifying the catA gene from the genus Gordonia (16 Gordonia representing 11 species). The amplified catA genes (382bp) were sequenced and analyzed. In the phylogenetic tree based on the translated catA amino acid sequences, all the Gordonia segregated clearly from other closely related genera. The sequence similarity of the catA gene in Gordonia ranged from 72.4% to 99.5%, indicating that the catA gene might have evolved faster than rrn operons or the gyrB gene at the inter-species level. A single nucleotide deletion of the catA gene was observed in Gordonia amicalis CC-MJ-2a, Gordonia rhizosphera and Gordonia sputi at nucleotide position 349. This deletion led to an encoding frame shift downstream of 11 amino acid residues, from WPSVAARAPAP to GHPWRPAHLHL, which was similar to most of the non-Gordonia Actinobacteria. Such variations might influence the catabolic activities or substrate utilization patterns of catechol 1,2-dioxygenase among Gordonia.

[Effects of soil moisture condition and phosphorus supply on the seedlings growth and phosphorus efficiency of Schima superba provenances].

Taking four representative Schima superba provenances from Longquan in Zhejiang, Jian'ou and Youxi in Fujian, and Ji'an in Jiangxi as test materials, and with the S. wallichii from Guangxi as the contrast, a pot experiment was conducted to study their seedlings growth and physiological responses under effects of different soil moisture condition and phosphorus supply. Significant differences were observed in the seedlings growth, root morphological parameters, and phosphorus absorption efficiency among the provenances under different soil moisture condition and phosphorus supply. The provenances from Jian'ou in Fujian and Longquan in Zhejiang exhibited larger growth increment, more developed root, and higher phosphorus absorption efficiency, compared with those from Youxi in Fujian and Ji'an in Jiangxi, while the S. wallichii from Guangxi Province remained its original characteristics of fast growing and drought and infertility resistance. Soil moisture condition and phosphorous supply had significant effects on the growth and development of S. superba. The seedlings growth, dry matter accumulation, root parameters, and phosphorus absorption efficiency were 18.5%-105.6% higher under appropriate soil moisture condition than under drought stress, and 37.5%-286.2% higher under high phosphorus than under low phosphorus supply. However, under drought stress and low phosphorus supply, S. superba seedlings allocated more photosynthetic products to their roots, and had higher phosphorus use efficiency, which could be an important physiological mechanism of the adaptation to drought stress and low phosphorus supply. Relative to the significant independent effects of provenance, watering level, and phosphorus supply, no significant interactive effects of the three factors were observed.