分类： 农、林、牧、渔 >> 农业基础学科 提交时间： 2023-11-13 合作期刊: 《干旱区科学》
摘要： Climate warming has led to the expansion of arable land at high altitudes, but it has also increased the demand for water use efficiency (WUE). To address this issue, the development of water-saving irrigation technology has become crucial in improving water productivity and economic returns. This study aimed to assess the impacts of three irrigation methods on water productivity and economic returns in wolfberry (Lycium barbarum L.) cultivation on the Tibetan Plateau, China during a two-year field trial. Results showed that subsurface irrigation with ceramic emitters (SICE) outperformed surface drip irrigation (DI) and subsurface drip irrigation (SDI) in terms of wolfberry yield. Over the two-year period, the average yield with SICE increased by 8.0% and 2.3% compared with DI and SDI, respectively. This improvement can be attributed to the stable soil moisture and higher temperature accumulation achieved with SICE. Furthermore, SICE exhibited higher WUE, with 14.6% and 4.5% increases compared with DI and SDI, respectively. In addition to the agronomic benefits, SICE also proved advantageous in terms of economic returns. Total average annual input costs of SICE were lower than the other two methods starting from the 8th year. Moreover, the benefit-cost ratio of SICE surpassed the other methods in the 4th year and continued to widen the gap with subsequent year. These findings highlight SICE as an economically viable water-saving irrigation strategy for wolfberry cultivation on the Tibetan Plateau. Thus, this research not only provides an effective water-saving irrigation strategy for wolfberry cultivation but also offers insights into addressing irrigation-related energy challenges in other crop production systems.
分类： 生物学 >> 生物物理学 >> 生物物理、生物化学与分子生物学 提交时间： 2016-05-11
Liu, Lian
Zhang, Shao-Wu
Zhang, Yu-Chen
Chen, Runsheng
Liu, Hui
Zhang, Lin
Chen, Runsheng
Huang, Yufei
Meng, Jia
摘要： Biochemical modifications to mRNA, especially N6-methyladenosine (m(6)A) and 5-methylcytosine (m(5)C), have been recently shown to be associated with crucial biological functions. Despite the intriguing advancements, little is known so far about the dynamic landscape of RNA methylome across different cell types and how the epitranscriptome is regulated at the system level by enzymes, i.e., RNA methyltransferases and demethylases. To investigate this issue, a meta-analysis of m(6)A MeRIP-Seq datasets collected from 10 different experimental conditions (cell type/tissue or treatment) is performed, and the combinatorial epitranscriptome, which consists of 42758 m(6)A sites, is extracted and divided into 3 clusters, in which the methylation sites are likely to be hyper- or hypo-methylated simultaneously (or co-methylated), indicating the sharing of a common methylation regulator. Four different clustering approaches are used, including K-means, hierarchical clustering (HC), Bayesian factor regression model (BFRM) and nonnegative matrix factorization (NMF) to unveil the co-methylation patterns. To validate whether the patterns are corresponding to enzymatic regulators, i.e., RNA methyltransferases or demethylases, the target sites of a known m(6)A regulator, fat mass and obesity-associated protein (FTO), are identified from an independent mouse MeRIP-Seq dataset and lifted to human. Our study shows that 3 out of the 4 clustering approaches used can successfully identify a group of methylation sites overlapping with FTO target sites at a significance level of 0.05 (after multiple hypothesis adjustment), among which, the result of NMF is the most significant (p-value 2.81 x 10(-06)). We defined a new approach evaluating the consistency between two clustering results which shows that clustering results of different methods are highly correlated strongly indicating the existence of co-methylation patterns. Consistent with recent studies, a number of cancer and neuronal disease-related bimolecular functions are enriched in the identified clusters, which are biological functions that can be regulated at the epitranscriptional level, indicating the pharmaceutical prospect of RNA N6-methyladenosine-related studies. This result successfully reveals the linkage between the global RNA co-methylation patterns embedded in the epitranscriptomic data under multiple experimental conditions and the latent enzymatic regulators, suggesting a promising direction towards a more comprehensive understanding of the epitranscriptome.
分类： 环境科学技术及资源科学技术 >> 环境科学技术基础学科 提交时间： 2019-10-26 合作期刊: 《干旱区科学》
XIONG Qinli
XIAO Yang
Marwa Waseem A HALMY
Mohammed A DAKHIL
LIANG Pinghan
LIU Chenggang
ZHANG Lin
Bikram PANDEY
PAN Kaiwen
Sameh B EL KAFRAWAY
CHEN Jun
摘要： Climate change and human activities can influence vegetation net primary productivity (NPP), a key component of natural ecosystems. The Qinghai-Tibet Plateau of China, in spite of its significant natural and cultural values, is one of the most susceptible regions to climate change and human disturbances in the world. To assess the impact of climate change and human activities on vegetation dynamics in the grassland ecosystems of the northeastern Qinghai-Tibet Plateau, we applied a time-series trend analysis to normalized difference vegetation index (NDVI) datasets from 2000 to 2015 and compared these spatiotemporal variations with trends in climatic variables over the same time period. The constrained ordination approach (redundancy analysis) was used to determine which climatic variables or human-related factors mostly influenced the variation of NDVI. Furthermore, in order to determine whether current conservation measures and programs are effective in ecological protection and reconstruction, we divided the northeastern Qinghai-Tibet Plateau into two parts: the Three-River Headwater conservation area (TRH zone) in the south and the non-conservation area (NTRH zone) in the north. The results indicated an overall (73.32%) increasing trend of vegetation NPP in grasslands throughout the study area. During the period 2000–2015, NDVI in the TRH and NTRH zones increased at the rates of 0.0015/a and 0.0020/a, respectively. Specifically, precipitation accounted for 9.2% of the total variation in NDVI, while temperature accounted for 13.4%. In addition, variation in vegetation NPP of grasslands responded not only to long- and short-term changes in climate, as conceptualized in non-equilibrium theory, but also to the impact of human activities and their associated perturbations. The redundancy analysis successfully separated the relative contributions of climate change and human activities, of which village population and agricultural gross domestic product were the two most important contributors to the NDVI changes, explaining 17.8% and 17.1% of the total variation of NDVI (with the total contribution >30.0%), respectively. The total contribution percentages of climate change and human activities to the NDVI variation were 27.5% and 34.9%, respectively, in the northeastern Qinghai-Tibet Plateau. Finally, our study shows that the grassland restoration in the study area was enhanced by protection measures and programs in the TRH zone, which explained 7.6% of the total variation in NDVI.
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