Complete genome of Mycolicibacterium phocaicum RL-HY01, a PAEs-degrading marine bacterial strain isolated from Zhanjiang Bay, China.

Mycolicibacterium phocaicum RL-HY01, a marine bacterial strain with the capability to degrade phthalic acid esters (PAEs), was isolated from Zhanjiang Bay, China. Here, the complete genome sequence of strain RL-HY01 was presented. The genome of strain RL-HY01 contains one circular chromosome of 6,064,759 bp with a G + C content of 66.93 mol%. The genome contains 5681 predicted protein-encoding genes, 57 tRNA genes, and 6 rRNA genes. Genes and gene clusters potentially involved in the metabolism of PAEs were further identified. The genome Mycolicibacterium phocaicum RL-HY01 will be helpful for advancing our understanding of the fate of PAEs in marine ecosystem.

Genome-wide identification and expression analysis of GDP-D-mannose pyrophosphorylase and KATANIN in Corymbia citriodora.

The GDP-D-mannose pyrophosphorylase (GMP) and microtubule severing enzyme KATANIN (KTN) are crucial for wood formation. Although functional identification has been performed in Arabidopsis, few comprehensive studies have been conducted in forest trees. In this study, we discovered 8 CcGMP and 4 CcKTN genes by analyzing the whole genome sequence of Corymbia citriodora. The chromosomal location, genome synteny, phylogenetic relationship, protein domain, motif identification, gene structure, cis-acting regulatory elements, and protein-interaction of CcGMP and CcKTN were all investigated. KTN has just one pair of segmentally duplicated genes, while GMP has no duplication events. According to gene structure, two 5' UTRs were identified in CcGMP4. Furthermore, there is no protein-interaction between KTN and GMP. Based on real-time PCR, the expression of most genes showed a positive connection with DBH diameters. In addition, the expression of CcGMP4 and CcKTN4 genes were greater in different size tree, indicating that these genes are important in secondary xylem production. Overall, this findings will enhance our comprehension of the intricacy of CcGMP&CcKTN across diverse DBHs and furnish valuable insights for future functional characterization of specific genes in C. citriodora.

Monitoring canopy recovery in a subtropical forest following a huge ice storm using hemispherical photography.

We estimated canopy structure and transmitted radiation using hemispherical photography in four monitoring years (2008-2010, 2016) following the 2008 huge ice storm in a subtropical forest in south China, so as to assess changes in canopy biophysical parameters during forest recovery from natural disturbance. Significant decrease in canopy openness (CO), transmitted direct radiation (TransDir), and transmitted diffuse radiation (TransDif), as well as significant increase in leaf area index (LAI), were found in the disturbed forest stand in the subsequent years following the ice storm, indicating rapid canopy recovery. In contrast, these biophysical parameters of the undisturbed forest stand were quite stable during the monitoring years. The strength of relationships between CO and other canopy biophysical parameters decreased in the disturbed stand along the monitoring years. The disturbed stand had common slopes for the CO-TransDir and CO-TransDif models in the first two monitoring years, but different slopes for the CO-LAI model between the first and the subsequent monitoring years, while the undisturbed stand had common slopes for all the regression models in the first three monitoring years following the huge ice storm. These results showed that stronger correlations of LAI or TransDir with CO were characteristic of less complex canopies, such as those damaged by disturbance; the sensitivity of transmitted radiation in response to CO decreased with canopy recovery. Our findings demonstrated that forests with different canopy structure varied in biophysical parameters, which can be quantified by hemispherical photography.

[Effects of topographic factors on the distribution patterns of ground plants with different growth forms in montane forests in North Guangdong, China].

By using canonical correspondence analysis (CCA), this paper studied the effects of small-scale topographic changes on the distribution patterns of ground plants with different growth forms in the montane evergreen broad-leaved forest in Chebaling National Nature Reserve of North Guangdong, China. It was observed that slope aspect, slope grade, and slope position had significantly integrative effects on the distribution patterns of four growth form ground plants (fern, liana, herb, and shrub). Slope aspect had significant effects on the distribution patterns of all four ground plants but slope position didn't have, whereas slope grade only affected the distribution pattern of shrub significantly. From shady slope to semi-shady slope, and to semi-sunny slope, the abundance of the four growth form ground plants decreased gradually, indicating that shade plants were dominant in the ground vegetation of subtropical montane evergreen broad-leaved forest. Most shrubs were shade-tolerant species, and their change patterns of richness and diversity with slope aspect were the same as the change pattern of abundance. Shrubs were sensitive to the change of slope grade, and richer on gentle slopes. In hilly and low mountains, slope position changed little, and had less effects on the distribution patterns of ground plants. At stand-level, horizontal topographic factor (slope grade aspect) had much greater effects on the distribution patterns of ground plants, as compared with vertical topographic factors (slope grade and slope position), which suggested that slope aspect was the major factor affecting the water and heat conditions in subtropical montane forest.