通讯机构：
[Chen, LJ; Wu, LC ] C;Cent South Univ Forestry & Technol, Key Lab Soil & Water Conservat & Desertificat Comb, Changsha 410004, Peoples R China.;Cent South Univ Forestry & Technol, Key Lab Cultivat & Protect Nonwood Forest Trees, Minist Educ, Changsha 410004, Peoples R China.
关键词：
Soil and water erosion;Soil property;Rainfall-runoff;Path analysis;Slash disposal methods
摘要：
BACKGROUND: The slash disposal-burning forest-in high-intensity management Eucalyptus grandis×urophylla plantation has accelerated soil degradation. STATEMENT OF THE PROBLEM: Slash disposals is a contributing factor, but its specific role in the correlation between rainfall-runoff and soil erosion remains elusive. OBJECTIVES: his study investigated the characteristics of rainfall-runoff and soil erosion resistance in different methods of slash disposals in plantation. METHODS: Three methods of slash disposal, namely burning forest (BF), moving away (MA), and spreading evenly (SE), were established. A field simulation experiment of rainfall was conducted, and path analysis was used. RESULTS: The findings revealed that the water holding, infiltrating properties and the time the rainfall-runoff generated of SE were increased by approximately 10∼20%, 100%, and 80%, respectively, compared with BF and MA. Water loss, soil loss and nutrient loss were significantly reduced by 62.23% and 61.56%, 69.06% and 49.55%, and 58.8% and 65.42% in SE and BF compared to MA. Path analysis suggested that different from BF and MA, the correlation between soil water properties and rainfall-runoff factors in SE was weakened, simultaneously considering the result that SE had the lower proportions of silt for sediment component (75.31%), it stabilized the soil structure. CONCLUSIONS AND PROSPECT: Consequently, SE mitigated the erosion force by reducing rainfall-runoff and enhancing the anti-erosion of soil through improved water properties, making it a viable slash disposal. This work provides a detailed description of the soil erosion characteristics of plantation, including water, soil, and nutrient losses caused by rainfall-runoff, as well as the soil anti-erosion due to different slash disposals. These findings offer valuable insights for the management of high-intensity Eucalyptus grandis×urophylla plantations.
作者机构：
[Zhu, Lingyue; Wu, Lichao; Chen, Lijun; Zhang, Lin] Cent South Univ Forestry & Technol, Coll Forestry, Key Lab Soil & Water Conservat & Desertificat Comb, Changsha, Hunan, Peoples R China.;[Wu, Qinzhan; Huang, Kangting; Chen, Zongfu] State Owned Daguishan Forest Farm, Hezhou, Guangxi, Peoples R China.;[Wen, Jianke] Guangxi Lvtuo Forestry CO LTD, Nanning, Guangxi, Peoples R China.;[Tang, Yabin; Li, Hui] Guangxi Diyuan Zhiben Fertilizer Co Ltd, Nanning, Guangxi, Peoples R China.;[Wu, Lichao] Cent South Univ Forestry & Technol, Key Lab Cultivat & Protect Nonwood Forest Trees, Natl Minist Educ, Changsha, Hunan, Peoples R China.
通讯机构：
[Wu, LC ] C;Cent South Univ Forestry & Technol, Coll Forestry, Key Lab Soil & Water Conservat & Desertificat Comb, Changsha, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Key Lab Cultivat & Protect Nonwood Forest Trees, Natl Minist Educ, Changsha, Hunan, Peoples R China.
摘要：
<jats:title>Abstract</jats:title><jats:p>Slash disposal changes soil quality by affecting soil properties and nutrient cycling, and the appropriate disposal approaches remain controversial. This work aimed to explore the impact of different slash disposal methods on soil qualities. For this purpose, a <jats:italic>Eucalyptus grandis</jats:italic> × <jats:italic>Eucalyptus urophylla</jats:italic> plantation that had been cultivated in 2002 and felled for the third time in 2016 was established in Hezhou City, China. Burning forest (BF, for moderate intensity fire) and no-burning forest (NF) were set in the plantation, and the native evergreen broadleaf forest near the plantation was used as the control (CK). Soils were sampled quarterly in 2017, and 27 indicators that represent soil physical, chemical, and biological properties were analyzed and compared through the analysis of the sustainability index (SI), which adopts five indices to calculate soil quality. The obtained data showed that the indicators of BF and NF, except for the total potassium content, were much lower than those of CK. The physical properties (Max-WHC, CWHC, Min-WHC, MMC, CPD, TPD) of NF were significantly better (29.07%, 30.98%, 29.61%, 52.08%, 21.89%, 19.76%) than those of BF, unlike the chemical properties of BF (SOM, TN, ACa, AFe, AMn, ACu, AZn) were significantly better than those of NF (45.61%, 81.33%, 12.78%, 23.18%, 96.13%, 144.30%, 114.04%). The enzymatic activities of NF (URE, APHO) were significantly better (43.33%, 156.58%)than those of BF, except the activities of INV (−25.21%). Results of SI showed that the soil quality of CK was much better than that of BF, and NF the worst. But it exhibited the most unevenness of CK, followed by NF, and BF the best. The change rules of BF and NF were contrasting, and soil quality reached the same level after half a year. In summary, the soil qualities, either BF or CK, were not comparable to that of CK. BF increased the soil quality fleetly and transiently, and NF was sustainable for the eucalyptus plantation.</jats:p>
摘要：
Leucine-rich repeat-containing genes (LRRs) have been reported to play important roles in responses to diseases. However, we poorly understood the response of LRRs to Fusarium wilt infection in tung tree (Vernicia fordii), which is an important economic tree. Here, 437 LRR-containing proteins containing nine types of LRR domains were identified in V. fordii genome. Phylogenetic analysis suggested that nine types of LRR domains could not be divided into separate classes, implying that these LRR domains had a common origin. Totally, 27 LRRs were related to possible resistance to Fusarium wilt after 2, 8, and 13 days post-inoculation. We further found that Vf06G1605 was up-regulate under Fusarium wilt infection after these three time points, Vf10G1602 and Vf02G1413 were up-regulated at 8, and 13 dpi, while Vf07G2320 was down-regulated at these three time points. The WGCNA and promoter elements suggested that WRKY possibly regulate the responses of LRRs to Fusarium wilt infection. This study highlighted the phylogeny and function of LRRs in V. fordii and provided a systematic analysis of these genes in the V. fordii genome. Our results presented here might clearly illustrate physiological mechanisms of resistance to Fusarium wilt infection and the target of marker-assisted breeding in V. fordii. (C) 2020 Elsevier B.V. All rights reserved.
通讯机构：
Key Laboratory of Cultivation and Protection for Non-wood Forest Trees, Key Laboratory of Non-wood Forest Products of Forestry Ministry, Central South University of Forestry and Technology, Changsha, China
关键词：
油桐;OFP基因家族;低温胁迫;响应分析
摘要：
OVATE Family Protein(OFP)蛋白是一类在非生物胁迫方面发挥着重要作用的新型植物转录调节因子,目前油桐中尚未报道。本文利用生物信息学的方法对油桐OFP基因家族成员的系统进化、基因结构、启动子元件等进行了预测和分析,并利用转录组数据和qRT-PCR技术研究了该家族成员的组织表达特性及低温响应模式。结果表明,油桐OFP基因家族有12个成员,可划分为4类,都存在OVATE 2结构域;染色体定位发现11个成员不均匀地分布在8条染色体上,且VfOFP6和VfOFP10存在共线性关系;启动子区共含有24类顺式作用元件,其中丰度较大的主要有光响应元件、厌氧诱导元件、激素响应相关元件、低温响应元件等;组织表达特性分析结果表明在根、叶、雌花和两性花、雄花、种子中主要表达的分别是VfOFP10、VfOFP6、VfOFP7、VfOFP12和VfOFP1;在低温胁迫条件下,VfOFP7在根、叶柄、叶中都显著诱导表达,而VfOFP16的表达量则显著下调,推测VfOFP7和VfOFP16可能在油桐响应低温胁迫调控中发挥重要作用,将为下一步开展基因的功能研究和油桐的遗传改良提供参考。
摘要：
Tung tree (Vernicia fordii), an economically important woody oil plant, is a monoecious and diclinous species with male and female flowers on the same inflorescence. The extremely low proportion of female flowers leads to low fruit yield in tung orchards. The female flower normally develops along with stamen abortion; otherwise sterile ovules will be produced. However, little knowledge is known about the molecular basis of the female flower development in tung tree. In this study, integrated analyses of morphological and cytological observations, endogenous phytohormone assay and RNA-seq were conducted to understand the molecular mechanism of the female flower development in tung tree. Cytological observation suggested that the abortion of stamens in female flowers (SFFs) belongs to the type of programmed cell death (PCD), which was caused by tapetum degeneration at microspore mother cell stage. A total of 1,366 differentially expressed genes (DEGs) were identified in female flowers by RNA-seq analysis, of which 279 (20.42%) DEGs were significantly enriched in phenylpropanoid biosynthesis, phenylalanine metabolism, flavonoid biosynthesis, starch and sucrose metabolism, and plant hormone signal transduction. Stage-specific transcript identification detected dynamically expressed genes of important transcription regulators in female flowers that may be involved in PCD and floral organ development. Gene expression patterns revealed that 17 anther and pollen development genes and 37 PCD-related genes might be involved in the abortion of SFF. Further analyses of phytohormone levels and co-expression networks suggested that salicylic acid (SA) accumulation could trigger PCD and inhibit the development of SFF in tung tree. This study provides new insights into the role of SA in regulating the abortion of SFF to develop normal female flowers.
关键词：
Anticodon;Lipid biosynthesis;tRNA;tRNA-derived RNA fragments;Tung tree
摘要：
Tung tree (Vernicia fordii Hemsl.) is a potential commercial source of biodiesel which is widely planted in China and many other countries. Investigation of the regulatory mechanism of lipid biosynthesis is an essential prerequisite to improve tung tree varieties by genetic engineering. In this study, the transfer RNA (tRNA) genes were identified in four genome-sequenced species (tung tree, rubber tree, castor bean and physic nut) in Euphorbiaceae. Gene clusters were observed for the four species tRNAs. Though tRNAs were highly conserved, contrasting patterns of nucleotide diversity were observed among the tRNA family. A total of 86 differentially expressed tRNA-derived RNA fragments (tRFs) were identified of which the target genes were enriched in lipid biosynthesis by Gene Ontology (GO) enrichment analysis. Interestingly, 11 lipid genes previously reported were identified and found to be regulated by 17 tRFs. A tRF-mRNA regulatory network was constructed, which provides a new insight into the genetic mechanism of lipid biosynthesis in tung tree.
关键词：
Vernicia fordii;SWEET genes;Expression;Internal repeat;Sucrose transport
摘要：
As a macromolecular substance, sucrose contributes to the plant growth and development. SWEET genes, a group of sugar transporters, are a recently found plant gene family and play important roles in sugar efflux, pollen nutrition, nectar secretion, phloem transport, and seed development. The SWEET genes have been identified and characterized in some plants, but the systematic study in tung tree (Vernicia fordii) was limited. Here, we identified 121 SWEETs in five Euphorbiaceae, and could be divided into four classes with 20 different motifs. Multiple sequence alignment revealed seven transmembrane helixes (TMHs) in the SWEET proteins which were created by an internal duplication of an ancestral three-TMHs unit, connected by TMH4. This study provides direct evidence for the first time for internal duplication in Euphorbiaceae. The large-scale duplication events represented the main driving force for SWEET family expansion in Euphorbiaceae. In addition, we determined the key VfSWEETs for sucrose transport from source to sink tissues in V. fordii and proposed a possible sucrose transport model, which would be helpful for understanding the mechanism of sucrose transport in V. fordii. This study provided a new insight into the evolution, expression and structural variations of SWEETs in V. fordii and four other Euphorbiaceae. (C) 2019 Published by Elsevier B.V.
