scholarly journals Effect of Sink-Limitation on Leaf Photosynthetic Rate and Related Characteristics in Soybean Plants

2008 ◽  
Vol 11 (2) ◽  
pp. 223-227 ◽  
Author(s):  
Minobu Kasai ◽  
Hideki Nakata ◽  
Hiroya Seino ◽  
Daisuke Kamata ◽  
Toshifumi Tsukiyama
2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Minobu Kasai ◽  
Keisuke Koide ◽  
Yuya Ichikawa

Despite the wide uses of potted plants, information on how pot size affects plant photosynthetic matter production is still considerably limited. This study investigated with soybean plants how transplantation into larger pots affects various characteristics related to photosynthetic matter production. The transplantation was analyzed to increase leaf photosynthetic rate, transpiration rate, and stomatal conductance without affecting significantly leaf intercellular CO2concentration, implicating that the transplantation induced equal increases in the rate of CO2diffusion via leaf stomata and the rate of CO2fixation in leaf photosynthetic cells. Analyses of Rubisco activity and contents of a substrate (ribulose-1,5-bisphosphate (RuBP)) for Rubisco and total protein in leaf suggested that an increase in leaf Rubisco activity, which is likely to result from an increase in leaf Rubisco content, could contribute to the transplantation-induced increase in leaf photosynthetic rate. Analyses of leaf major photosynthetic carbohydrates and dry weights of source and sink organs revealed that transplantation increased plant sink capacity that uses leaf starch, inducing a decrease in leaf starch content and an increase in whole plant growth, particularly, growth of sink organs. Previously, in the same soybean species, it was demonstrated that negative correlation exists between leaf starch content and photosynthetic rate and that accumulation of starch in leaf decreases the rate of CO2diffusion within leaf. Thus, it was suggested that the transplantation-induced increase in plant sink capacity decreasing leaf starch content could cause the transplantation-induced increase in leaf photosynthetic rate by inducing an increase in the rate of CO2diffusion within leaf and thereby substantiating an increase in leaf Rubisco activity in vivo. It was therefore concluded that transplantation of soybean plants into larger pots attempted in this study increased the plant photosynthetic matter production by increasing mainly sink capacity that uses leaf starch for whole plant growth, particularly, growth of sink organs.


2018 ◽  
Vol 10 (11) ◽  
pp. 4063 ◽  
Author(s):  
Yue Li ◽  
Lei Zhou ◽  
Shaoqiang Wang ◽  
Yonggang Chi ◽  
Jinghua Chen

Photosynthesis is arguably the most important biochemical process on Earth, which is dramatically influenced by environmental conditions. How environmental factors drive stomatal conductance and biochemical processes of leaf photosynthetic rate has not been sufficiently investigated in subtropical China. In this study, we analysed the effects of stomatal and biochemical parameters on the photosynthetic rate of native Masson’s pine (Pinus massoniana Lamb.) and exotic slash pine (Pinus elliottii Engelm.) in response to leaf temperature and vapour pressure deficit (VPD) in subtropical China, based on leaf gas exchange measurements in 2016. Our results showed that there was no significant difference in the light-saturated photosynthetic rate (Asat) between native Masson’s pine and exotic slash pine. The seasonal patterns of maximum rate of the carboxylation (Vcmax25) were basically consistent with seasonal patterns of Asat for both species. The positive effect of leaf temperature on Asat was mainly produced through its positive effect on Vcmax25. Leaf temperature had no significant effect on stomatal conductance. Vcmax25 and gs simultaneously affected Asat in response to VPD. Our results highlighted the importance of biochemical processes in limiting leaf photosynthetic rate in response to environmental conditions in subtropical evergreen coniferous plantations.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1527
Author(s):  
Carolina Rivera-Amado ◽  
Gemma Molero ◽  
Eliseo Trujillo-Negrellos ◽  
Matthew Reynolds ◽  
John Foulkes

Grain filling may be limited by the joint source and sink capacity in modern wheat cultivars, indicating a need to research the co-limitation of yield by both photosynthesis and the number and potential size of grains. The extent to which the post-anthesis source may be limiting final grain size can be estimated by partial degraining of spikes, while defoliation and shading treatments can be useful to estimate if any excess photosynthetic capacity exists. In the current study, degraining was applied to a set of 26 elite spring wheat cultivars from the International Maize and Wheat Improvement Center (CIMMYT)’s core germplasm (CIMCOG) panel, while lamina defoliation and shading through stem-and-leaf-sheath covering treatments were applied to a subset of the same cultivars. Responses to source treatments in grain weight, pre-anthesis reserve contribution to grain weight, dry-matter translocation efficiency, and flag-leaf and spike photosynthetic rate were measured and compared to an unmanipulated control treatment. Grain weight responses to degraining among cultivars ranged from no response to increases of 28%, suggesting a range of responses from sink limitation, to probable source and sink co-limitation of grain growth. Grain weight’s response to degraining increased linearly with the years of cultivar release from 1966 to 2009, indicating that the current highest yield potential CIMMYT spring wheats have a co-limitation of grain growth by source and sink. This may have been due to an increase in grain sink strength with years of cultivar release with no commensurate increase in post-anthesis source capacity. The relatively low decreases in grain weight with defoliation compared to decreases in light interception by defoliation indicated that sink limitation was still likely predominating in the cultivars with co-limitation. The stem-and-leaf-sheath covering treatment decreased grain weight by nearly 10%, indicating that stem-and-leafsheath photosynthesis plays a key role in grain growth during grain filling. In addition, pre-anthesis reserve contribution to grain weight was increased by ca. 50% in response to lamina defoliation. Our results showed that increasing the post-anthesis source capacity, through increases in stem-and-leaf-sheath photosynthetic rate during grain filling and pre-anthesis reserve contribution to grain weight, is an important objective in enhancing yield potential in wheat through maintaining a source–sink balance.


Euphytica ◽  
2004 ◽  
Vol 135 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Sheng Teng ◽  
Qian Qian ◽  
Dali Zeng ◽  
Yasufumi Kunihiro ◽  
Kan Fujimoto ◽  
...  

2001 ◽  
Vol 49 (4) ◽  
pp. 509 ◽  
Author(s):  
Wen-Yuan Kao ◽  
Kuo-Wei Chang

Leaf photosynthetic rate and leaf characteristics including chlorophyll content, leaf width, leaf mass per area (LMA), stomatal density and the dimensions of guard cells were measured in C 4 Miscanthus spp. growing along an altitudinal gradient from 390 to 2700 m in central Taiwan. The main objective of this study was to understand if morphological and physiological variation occur in leaves of the C 4 plants growing along the altitudinal gradient. Measurements were taken during the growing season, May, July and September, of 1997. Photosynthetic rate, leaf width and guard cell dimensions decreased while LMA and stomatal density increased with altitude. The pattern of continuous variation in the analysed parameters suggests that it is related to some underlying environmental factors (mainly air temperature and CO 2 concentration) associated with changing altitude.


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