英语翻译Crassulacean acid metabolism (CAM),a water-conservingmode of photosynthesis whereby plants take up CO2 atnight,has been under investigation since its discovery over200 years ago (Winter and Smith 1996).It has evolvedmultiple times in near
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英语翻译Crassulacean acid metabolism (CAM),a water-conservingmode of photosynthesis whereby plants take up CO2 atnight,has been under investigation since its discovery over200 years ago (Winter and Smith 1996).It has evolvedmultiple times in near
英语翻译
Crassulacean acid metabolism (CAM),a water-conserving
mode of photosynthesis whereby plants take up CO2 at
night,has been under investigation since its discovery over
200 years ago (Winter and Smith 1996).It has evolved
multiple times in nearly 30 plant families,both terrestrial
and aquatic (Crayn et al.2004;Lu¨ttge 2004),and is found
in at least 6% of all vascular plant species (Ehleringer and
Monson 1993).There are four phases of CAM:(1) night-
time CO2 uptake and fixation by phosphoenolpyruvate
carboxylase (PEPC),(2) early morning CO2 uptake and
fixation by ribulose 1,5-bisphosphate carboxylase/oxygen-
ase (Rubisco),(3) daytime decarboxylation and refixation
of CO2 under closed stomates,and (4) late afternoon CO2
uptake and fixation by Rubisco (Griffiths et al.2002;
Lu¨ttge 2004).Although CAM is typically defined as
nighttimeCO2 uptake,inmanyCAMspecies,daytimeCO2
fixation by Rubisco raises questions as to whether the
amount of CO2 fixed through the C3 pathway varies with
environmental conditions (e.g.,Nobel et al.1992; Winter
and Holtum 2002; Winter et al.2008).The significance ofvariation in activity of Rubisco in strong CAM plants has
not yet been fully incorporated into an ecological
framework.
13
The C stable isotopic composition (d C) of plant
material can be used as an indicator of the relative pro-
portion of CO2 assimilated by CAM and C3 photosynthetic
pathways because of differential discrimination by the
two carboxylating enzymes,PEPC and Rubisco.If only
Rubisco is used,as occurs during light CO2 fixation,the
13
d C of bulk plant material will be close to -27%.In
contrast,if only PEPC is used,as occurs during dark CO2
13
fixation,the d C of plant material will be near -13%.
13
Foliar d C values therefore reflect the weighting of these
two processes (Farquhar et al.1989).A mixing model
13
using plant d C values in combination with CAM and C3
can provide information on the proportional use of the two
photosynthetic pathways.Moreover,taking into consider-
ation variation in C3 and CAM activity can allow a more
accurate description of the contribution of each photosyn-
thetic pathway (Winter and Holtum 2002).
英语翻译Crassulacean acid metabolism (CAM),a water-conservingmode of photosynthesis whereby plants take up CO2 atnight,has been under investigation since its discovery over200 years ago (Winter and Smith 1996).It has evolvedmultiple times in near
Crassulacean acid metabolism (CAM),a water-conserving Crassulacean酸代谢(CAM)的,一个节水
mode of photosynthesis whereby plants take up CO2 at植物光合作用的模式,即在采取了二氧化碳
night,has been under investigation since its discovery over晚上,一直受到了调查,发现自
200 years ago (Winter and Smith 1996).200年前(冬季和史密斯1996年).It has evolved它已演变
multiple times in nearly 30 plant families,both terrestrial多次在近30个植物科,陆地
and aquatic (Crayn et al.2004;Lu¨ttge 2004),and is found和水产品(Crayn等人.2004年;路¨ ttge 2004年),被发现
in at least 6% of all vascular plant species (Ehleringer and至少在所有维管植物6种(Ehleringer和%
Monson 1993).蒙森1993年).There are four phases of CAM:(1) night-有四种CAM的阶段:(1)夜间
time CO2 uptake and fixation by phosphoenolpyruvate二氧化碳吸收和固定的时间由磷酸
carboxylase (PEPC),(2) early morning CO2 uptake and羧化酶(PEPC公司),(二)清晨二氧化碳的吸收和
fixation by ribulose 1,5-bisphosphate carboxylase/oxygen-固定的核酮糖1,5二磷酸carboxylase/oxygen-
ase (Rubisco),(3) daytime decarboxylation and refixation酶(Rubisco活化酶),(3)白天脱羧和refixation
of CO2 under closed stomates,and (4) late afternoon CO2二氧化碳在封闭stomates,(4)傍晚二氧化碳
uptake and fixation by Rubisco (Griffiths et al.2002;吸收和Rubisco的固定(格里菲斯等人.2002年;
Lu¨ttge 2004).路¨ ttge 2004年).Although CAM is typically defined as锦雯虽然通常定义为
nighttimeCO2 uptake,inmanyCAMspecies,daytimeCO2 nighttimeCO2吸收,inmanyCAMspecies,daytimeCO2
fixation by Rubisco raises questions as to whether the由Rubisco的固定的问题提出疑问是否
amount of CO2 fixed through the C3 pathway varies with二氧化碳数量,通过固定的C3途径各有不同
environmental conditions (eg,Nobel et al.1992; Winter (如环境条件,诺贝尔等人.1992年;冬季
and Holtum 2002; Winter et al.2002年和霍尔图姆;冬季等.2008).2008年).The significance ofvariation in activity of Rubisco in strong CAM plants has在强大的CAM植物的Rubisco活性有重要意义ofvariation
not yet been fully incorporated into an ecological尚未完全纳入生态
framework.框架.
13 13
The C stable isotopic composition (d C) of plant稳定同位素组成的C(四三)植物
material can be used as an indicator of the relative pro-材料可作为一个指标的相对亲
portion of CO2 assimilated by CAM and C3 photosynthetic部分由CAM的光合作用吸收二氧化碳和C3
pathways because of differential discrimination by the因为微分歧视的途径
two carboxylating enzymes,PEPC and Rubisco.二carboxylating酶,PEPC和Rubisco的.If only如果只
Rubisco is used,as occurs during light CO2 fixation,the Rubisco的使用,因为在轻固定CO2,发生的
13 13
d C of bulk plant material will be close to -27%.In Ð的植物原料C将接近-27%.在
contrast,if only PEPC is used,as occurs during dark CO2相比之下,如果只有转PEPC使用,因为在黑暗的二氧化碳发生
13 13
fixation,the d C of plant material will be near -13%.固定,植物Ð C材料将接近13%.
13 13
Foliar d C values therefore reflect the weighting of these因此,叶面喷施Ð C值反映了这些比重
two processes (Farquhar et al.1989).两个进程(法夸尔等.1989年).A mixing model一个混合模式
13 13
using plant d C values in combination with CAM and C3利用植物Ð C值与CAM的结合和C3
can provide information on the proportional use of the two可以提供关于这两个比例使用信息
photosynthetic pathways.光合作用途径.Moreover,taking into consider-此外,考虑到考虑,
ation variation in C3 and CAM activity can allow a more款中的C3和CAM的活动可以让更多的变化
accurate description of the contribution of each photosyn-准确地描述了每个光合作用的贡献,
thetic pathway (Winter and Holtum 2002).正题途径(2002年冬,霍尔图姆).
Crassulacean酸代谢(CAM)的,一个节水
植物光合作用的模式,即在采取了二氧化碳
晚上,一直受到了调查,发现自
200年以前(1996年冬,史密斯)。它已演变
多次在近30个植物科,陆地
和水产品(Crayn等人。2004年;路¨ ttge 2004年),被发现
至少在所有维管植物6种(Ehleringer和%
蒙森...
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Crassulacean酸代谢(CAM)的,一个节水
植物光合作用的模式,即在采取了二氧化碳
晚上,一直受到了调查,发现自
200年以前(1996年冬,史密斯)。它已演变
多次在近30个植物科,陆地
和水产品(Crayn等人。2004年;路¨ ttge 2004年),被发现
至少在所有维管植物6种(Ehleringer和%
蒙森1993年)。有四种CAM的阶段:(1)夜间
二氧化碳吸收和固定的时间由磷酸
羧化酶(PEPC公司),(二)清晨二氧化碳的吸收和
固定的核酮糖1,5二磷酸carboxylase/oxygen-
酶(Rubisco活化酶),(3)白天脱羧和refixation
二氧化碳在封闭stomates,(4)傍晚二氧化碳
吸收和Rubisco的固定(格里菲斯等人。2002年;
路¨ ttge 2004年)。锦雯虽然通常定义为
nighttimeCO2吸收,inmanyCAMspecies,daytimeCO2
由Rubisco的固定的问题提出疑问是否
二氧化碳数量,通过固定的C3途径各有不同
(如环境条件,诺贝尔等人。1992年;冬季
2002年和霍尔图姆;冬季等。 2008年)。在强大的CAM植物的Rubisco活性有重要意义ofvariation
尚未完全纳入生态
框架。
13
稳定同位素组成的C(四三)植物
材料可作为一个指标的相对亲
部分由CAM的光合作用吸收二氧化碳和C3
因为微分歧视的途径
二carboxylating酶,PEPC和Rubisco的。如果只
Rubisco的使用,因为在轻固定CO2,发生的
13
Ð的植物原料C将接近-27%。在
相比之下,如果只有转PEPC使用,因为在黑暗的二氧化碳发生
13
固定,植物Ð C材料将接近13%。
13
因此,叶面喷施Ð C值反映了这些比重
两个进程(法夸尔等。1989年)。一个混合模式
13
利用植物Ð C值与CAM的结合和C3
可以提供关于这两个比例使用信息
光合作用途径。此外,考虑到考虑,
款中的C3和CAM的活动可以让更多的变化
准确地描述了每个光合作用的贡献,
正题途径(2002年冬,霍尔图姆)。
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