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THE 4C APPROACH AS A WAY TO UNDERSTAND SPECIES INTERACTIONS DETERMINING INTERCROPPING PRODUCTIVITY

《农业科学与工程前沿(英文)》 2021年 第8卷 第3期   页码 387-399 doi: 10.15302/J-FASE-2021414

摘要:

Modern agriculture needs to develop transition pathways toward agroecological, resilient and sustainable farming systems. One key pathway for such agroecological intensification is the diversification of cropping systems using intercropping and notably cereal-grain legume mixtures. Such mixtures or intercrops have the potential to increase and stabilize yields and improve cereal grain protein concentration in comparison to sole crops. Species mixtures are complex and the 4C approach is both a pedagogical and scientific way to represent the combination of four joint effects of Competition, Complementarity, Cooperation, and Compensation as processes or effects occurring simultaneously and dynamically between species over the whole cropping cycle. Competition is when plants have fairly similar requirements for abiotic resources in space and time, the result of all processes that occur when one species has a greater ability to use limiting resources (e.g., nutrients, water, space, light) than others. Complementarity is when plants grown together have different requirements for abiotic resources in space, time or form. Cooperation is when the modification of the environment by one species is beneficial to the other(s). Compensation is when the failure of one species is compensated by the other(s) because they differ in their sensitivity to abiotic stress. The 4C approach allows to assess the performance of arable intercropping versus classical sole cropping through understanding the use of abiotic resources.

 

关键词: compensation     competition     complementarity     cooperation     interspecific interactions     land equivalent ratio     light     nutrients     species mixtures     water    

Development of the expressed immunoglobulin μ chain repertoire during maturation of mice B cells

Jingwen LIANG,Yingfeng LUO,Yi SUN,Meng LEI,Bing ZHANG,Songnian HU,Yaofeng ZHAO

《农业科学与工程前沿(英文)》 2014年 第1卷 第3期   页码 201-213 doi: 10.15302/J-FASE-2014017

摘要: In the bone marrow and spleen, the developing B cell populations undergo both negative and positive selections to shape their B cell receptor repertoire. To gain insight into the shift of the immunoglobulin heavy (IgH) chain repertoire during B cell development, we undertook large scale Ig μ chain repertoire analysis of pre-B, immature B and spleen B cell populations. We found that the majority of V gene segments, V families, J and D gene segments, were observed to have significantly different usage frequencies when three B cell populations were compared, but the usage profile of the V D, and J genes between different B cell populations showed high correlations. In both productive and nonproductive rearrangements, the length of CDRH3 shortened significantly on average when B cells entered the periphery. However, the CDRH3 length distribution of nonproductive rearrangements did not follow a Gaussian distribution, but decreased successively in the order 3 -2, 3 -1 and 3 , suggesting a direct correlation between mRNA stability and CDRH3 length patterns of nonproductive rearrangements. Further analysis of the individual components comprising CDRH3 of productive rearrangements indicated that the decrease in CDRH3 length was largely due to the reduction of N addition at the 5′ and 3′ junctions. Moreover, with development, the amino acid content of CDRH3 progressed toward fewer positively charged and nonpolar residues but more polar residues. All these data indicated that the expressed Ig μ chain repertoire, especially the repertoire of CDRH3, was fine-tuned when B cells passed through several checkpoints of selection during the process of maturation.

关键词: repertoire     complementarity determining region 3 of the IgH chain (CDRH3)     immunoglobulin     heavy chain     variable region    

标题 作者 时间 类型 操作

THE 4C APPROACH AS A WAY TO UNDERSTAND SPECIES INTERACTIONS DETERMINING INTERCROPPING PRODUCTIVITY

期刊论文

Development of the expressed immunoglobulin μ chain repertoire during maturation of mice B cells

Jingwen LIANG,Yingfeng LUO,Yi SUN,Meng LEI,Bing ZHANG,Songnian HU,Yaofeng ZHAO

期刊论文