CARBON DIOXIDE EXCHANGE RATES OF FRUITING SOYBEAN PLANTS EXPOSED TO OZONE AND SULPHUR DIOXIDE SINGLY OR IN COMBINATION

1984 ◽  
Vol 64 (1) ◽  
pp. 69-75 ◽  
Author(s):  
N. M. LE SUEUR-BRYMER ◽  
D. P. ORMROD

Carbon dioxide exchange rates (CER) of intact soybean (Glycine max (L.) Merr.) plants at the fruiting stage were measured in continuous stirred tank reactor (CSTR) chambers. Plants were exposed to clean air, 67 ppb ozone (O3), 300 ppb sulphur dioxide (SO2), or 67 ppb O3 plus 300 ppb SO2 for 7.5 h∙day−1 for 5 days. Carbon dioxide exchange rates were measured hourly during the last 6 h of each exposure period and decreased progressively during the first period of exposure to O3 plus SO2, dropping in hour 6 to 42% of the hour 1 rate, and to a lesser extent in the second daily exposure when the corresponding decline was to 70%. There was a declining trend in CER of SO2-treated but not O3-treated plants with increasing number of days of exposure. Carbon dioxide exchange rates of all plants generally peaked and declined during each exposure period.Key words: Air pollution, net photosynthesis, mixtures, Glycine max

1985 ◽  
Vol 65 (2) ◽  
pp. 267-274 ◽  
Author(s):  
B. I. CHEVONE ◽  
Y. S. YANG

Soybean (Glycine max (L.) Merr. ’Essex’) plants, 21–24 days old, were exposed to 400 μg/m3 (0.20 μL/L) ozone (O3) and 1865 μg/m3 (0.70 μL/L) sulfur dioxide (SO2) in various combinations. Fumigation was administered for 2 h either as single pollutants (O3 and SO2), simultaneously (O3 + SO2), or in overlapping pollutant combinations (O3 for 1 h followed by O3 + SO2 or SO2 for 1 h followed by SO2 + O3). Carbon dioxide exchange rates (CER) of trifoliolate leaves were measured during the fumigations, and stomatal resistance to H2O was determined immediately before and after pollutant exposure. At the end of a 2-h exposure, O3 and SO2, administered separately, did not significantly affect CER. Exposure to O3 followed by O3 + SO2, SO2 followed by SO2 + O3, and continuous O3 + SO2 significantly reduced CER to 62, 41 and 33% of preexposure rates, respectively. Stomatal resistance was not significantly altered by pollutant fumigation except in the simultaneous application of O3 + SO2 where an 11% decrease occurred. Reductions in CER in response to fumigation were not attributed to changes in stomatal resistance, but appeared to result from changes in mesophyll resistance. A proposed mechanism for pollutant-induced reduction in CER is discussed.Key words: Air pollution, net photosynthesis, pollutant mixtures


2021 ◽  
Vol 219 ◽  
pp. 112312
Author(s):  
Yinlong Xiao ◽  
Ying Du ◽  
Yue Xiao ◽  
Xiaohong Zhang ◽  
Jun Wu ◽  
...  

2021 ◽  
Vol 22 (2) ◽  
pp. 920
Author(s):  
Ling Cheng ◽  
Wanling Min ◽  
Man Li ◽  
Lili Zhou ◽  
Chuan-Chih Hsu ◽  
...  

Soybean (Glycine max L.) is a major crop providing important source for protein and oil for human life. Low phosphate (LP) availability is a critical limiting factor affecting soybean production. Soybean plants develop a series of strategies to adapt to phosphate (Pi) limitation condition. However, the underlying molecular mechanisms responsible for LP stress response remain largely unknown. Here, we performed a label-free quantification (LFQ) analysis of soybean leaves grown under low and high phosphate conditions. We identified 267 induced and 440 reduced differential proteins from phosphate-starved leaves. Almost a quarter of the LP decreased proteins are involved in translation processes, while the LP increased proteins are accumulated in chlorophyll biosynthetic and carbon metabolic processes. Among these induced proteins, an enolase protein, GmENO2a was found to be mostly induced protein. On the transcriptional level, GmENO2a and GmENO2b, but not GmENO2c or GmENO2d, were dramatically induced by phosphate starvation. Among 14 enolase genes, only GmENO2a and GmENO2b genes contain the P1BS motif in their promoter regions. Furthermore, GmENO2b was specifically induced in the GmPHR31 overexpressing soybean plants. Our findings provide molecular insights into how soybean plants tune basic carbon metabolic pathway to adapt to Pi deprivation through the ENO2 enzymes.


2014 ◽  
Vol 7 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Bruno Henrique Sardinha de Souza ◽  
Eduardo Neves Costa ◽  
Anderson Gonçalves da Silva ◽  
Arlindo Leal Boiça Júnior

A soja, Glycine max (L.) Merril, é uma das culturas de maior importância econômica para o Brasil, considerada uma commodity nacional devido à sua alta produtividade e participação nas exportações no mercado internacional. Dentre os insetos-pragas que causam danos para essa cultura, nos últimos anos agrícolas têm merecido destaque as lagartas de Spodoptera eridania (Cramer), as quais podem se alimentar tanto de folhas quanto das vagens das plantas de soja, causando prejuízos econômicos para os sojicultores, principalmente nas áreas do Cerrado localizadas na região Centro-Oeste do país. O objetivo da presente revisão é disponibilizar informações sobre os aspectos bionômicos de S. eridania, a fim de dar subsídios para futuras pesquisas sobre o manejo dessa praga.Bionomic Aspects of Spodoptera eridania (Cramer): A Pest in Expansion on Soybean Crop in the Region of Brazilian CerradoAbstract. Soybean, Glycine max (L.) Merril, represents one of the major economically important crops to Brazil, and is considered a national commodity because of its high yield and participation in international trade exportations. Among the insect pests that cause damage to this crop, Spodoptera eridania (Cramer) larvae highlighted in the last agricultural seasons by feeding on leaves and pods of soybean plants, and hence causing economical losses to soybean growers, especially in the Cerrado areas located in the Midwest region of the country. We aimed with this review to provide information about bionomical aspects of S. eridania in order to give subsides for further researches on the management of this pest.


1998 ◽  
Vol 27 (4) ◽  
pp. 513-518 ◽  
Author(s):  
Mauro T. B. Silva ◽  
Nelson Neto ◽  
Clara B. Hoffmann-Campo

Soybean [(Glycine max (L.) Merrill] commercial fields, maintained under a no-till system, were sampled during the crop seasons 1990/91 and 1996/97, in Cruz Alta and Júlio de Castilhos, Rio Grande do Sul State, to determine the distribution of eggs, larvae and adults of Sternechus subsignatus Boheman (Coleoptera : Curculionidae). Soybean plants and soil were examined at different time schedules. Eggs and larvae were recorded in main stems, lateral branches and leaf petioles, divided into the upper third, medium and lower third of soybean plants. Eggs (87%), and larvae (79%) were mainly observed in the main stem and in the medium plant sections (87% and 78%, respectively). Larval movement was not observed because larvae remained inside the galls, in the same area where the eggs were laid. Adults were located in different places depending on the sampling time. At night, adults were observed to move to the upper third of the plant and, during the day, down to the lower third of the plant and to the soil. The insects are normally concealed during their pre- and post- embryonic stage throughout most of the day.


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