Changes in the osmotic potential of the root as a factor in the decrease in the root-shoot ratio ofZea mays plants under water stress

Studying the specific effects of water and nutrients on plant development is difficult because changes in a single component can often trigger multiple response pathways. Such confounding issues are prevalent in commonly used laboratory assays. For example, increasing the nitrate concentration in growth media alters both nitrate availability and osmotic potential. In addition, it was recently shown that a change in the osmotic potential of media alters the plant's ability to take up other nutrients such as sucrose. It can also be difficult to identify the initial target tissue of a particular environmental cue because there are correlated changes in development of many organs. These growth changes may be coordinately regulated, or changes in development of one organ may trigger changes in development of another organ as a secondary effect. All these complexities make analyses of plant responses to environmental factors difficult to interpret. Here, we review the literature on the effects of nitrate, sucrose and water availability on root system growth and discuss the mechanisms underlying these effects. We then present experiments that examine the impact of nitrate, sucrose and water on root and shoot system growth in culture using an approach that holds all variables constant except the one under analysis. We found that while all three factors also alter root system size, changes in sucrose and osmotic potential also altered shoot system size. In contrast, we found that, when osmotic effects are controlled, nitrate specifically inhibits root system growth while having no effect on shoot system growth. This effectively decreases the root : shoot ratio. Alterations in root : shoot ratio have been widely observed in response to nitrogen starvation, where root growth is selectively increased, but the present results suggest that alterations in this ratio can be triggered across a wide spectrum of nitrate concentrations.

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Greenhouse production of Echinacea purpurea (L.) and E. angustifolia using different growing media, NO3−/NH4+ ratios and watering regimes

Canadian Journal of Plant Science ◽

10.4141/p05-167 ◽

2006 ◽

Vol 86 (3) ◽

pp. 809-815 ◽

Cited By ~ 5

Author(s):

Youbin Zheng ◽

Mike Dixon ◽

Praveen Saxena

Keyword(s):

Water Stress ◽

Medicinal Plant ◽

Leaf Area ◽

Production System ◽

Echinacea Purpurea ◽

Root Production ◽

Total Biomass ◽

Greenhouse Production ◽

Shoot Ratio ◽

Root Shoot Ratio

Current field cultivation and wild-harvest methods for the medicinal plant Echinacea are struggling to meet the requirements for a high-quality, uniformly produced crop for human consumption. To help meet this challenge, the potential of using a greenhouse production system for Echinacea production was explored. Echinacea purpurea (L.) Moench and angustifolia DC. var. angustifolia plants were grown in three types of greenhouse production systems: (1) deep flow solution culture (D), (2) pots with either Pro-Mix (P) or (3) sand (S). Plants were irrigated with one of three nutrient solutions containing NO3−/NH4+ ratios of 7:1, 5:1 or 3:1, respectively. The plants grown in the Pro-Mix and the sand systems were either well-watered or subjected to periodical water stress. The results obtained after 12 wk of growth showed that Echinacea root production in the greenhouse systems was comparable with or better than that in the field. Based on root and total biomass production, the Pro-Mix system was the best production system for both E. angustifolia and E. purpurea. In most cases, the NO3−/NH4+ ratio did not have significant effects on the growth of either species. When effects were seen, however, higher NO3−/NH4+ levels generally resulted in greater leaf area, root and total biomass, and a higher root/shoot ratio. Mild periodic water stress did not affect the root/shoot ratio or the root biomass in either species. The application of a periodic water stress reduced leaf area of both species, but a reduction in total biomass was only observed in E. purpurea. Key words: Echinacea, greenhouse production, hydroponic production, medicinal plant, NO3−/NH4+ ratio, water stress

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DROUGHT-TOLERANT MAIZE GENOTYPES INVEST IN ROOT SYSTEM AND MAINTAIN HIGH HARVEST INDEX DURING WATER STRESS

Revista Brasileira de Milho e Sorgo ◽

10.18512/rbms.v15i3.842 ◽

2017 ◽

Vol 15 (3) ◽

pp. 450

Author(s):

RONIEL GERALDO AVILA ◽

PAULO CESÁR MAGALHÃES ◽

AMAURI ALVES DE ALVARENGA ◽

ALYNE DE OLIVEIRA LAVINSKY ◽

CLEIDE NASCIMENTO CAMPOS ◽

...

Keyword(s):

Water Stress ◽

Root System ◽

Dry Weight ◽

Carbon Partitioning ◽

Gas Exchanges ◽

Drought Tolerant ◽

Shoot Ratio ◽

Root Shoot Ratio ◽

Maize Genotypes ◽

Source Sink

ABSTRACT – Drought is considered the primary limitation to agriculture and, can reduce grain yield by up to 60%when occurs at pre-flowering in maize. In this context this research, aimed to understand the maize genotypes behaviorto drought management and carbon partitioning between grain production and structures to maintain hydration whensubmitted to drought. Maize genotypes tolerant (DKB390 and P30F35) and sensitive (BRS1010 and 2B710) to droughtwere grown in a greenhouse using two water conditions: irrigated and stressed. Water deficit was imposed atpre-flowering and maintained for twelve days. Leaf water potential, gaseous exchange and male and female floweringinterval were evaluated. At the end of the cycle, production components and root/shoot ratio dry weight were evaluated.Drought-tolerant genotypes used root system as a mechanism of tolerance to drought, which ensure greater efficiencyin absorption and loss of water and, consequently, greater stomatal conductance during the drought, compared to thesensitive-genotypes. In addition, drought-tolerant genotypes showed greater stability in the source-sink relationship,exhibiting higher photosynthetic rate and harvest index.Keywords: water stress, carbon partitioning; root/shoot ratio dry weight, gas exchanges, Zea mays.GENÓTIPOS DE MILHO TOLERANTES À SECA INVESTEM EM SISTEMA RADICULARE MANTEM ALTO ÍNDICE DE COLHEITA DURANTE O ESTRESSE HÍDRICORESUMO- A seca é considerada restrição primária à agricultura, e no milho, quando ocorre no pré-florescimento,pode reduzir o rendimento de grãos em até 60%. Neste contexto, objetivou-se entender como genótipos de milhocontrastantes para tolerância à seca, gerenciam o particionamento de carbono entre produção de grãos e estruturasde manutenção da hidratação durante a seca. Para isso, em casa de vegetação cultivaram-se genótipos de milhotolerantes (DKB390 e P30F35) e sensíveis (BRS1010 e 2B710) à seca, em duas condições hídricas: irrigadonormal e déficit hídrico. No pré-florecimento foi imposto o déficit hídrico, que foi mantido por doze dias.Posteriormente avaliou-se o potencial hídrico foliar, trocas gasosas e intervalo de florescimento masculino e feminino.No final do ciclo, avaliaram-se os componentes de produção e a razão raiz/parte aérea. Constatou-se que, genótipostolerantes utilizaram preferencialmente sistema radicular como um mecanismo de tolerância à seca, o que garantiu aesses genótipos, maior eficiência entre a absorção e perda de água e, consequentemente, maior condutância estomáticadurante a seca, em relação aos genótipos sensíveis. Além disso, os genótipos tolerantes apresentaram maior equilíbrioem suas relações fonte e dreno, exibindo maiores taxa fotossintética e índice de colheita.Palavras-chave: estresse hídrico, particionamento de carbono, razão raiz/parte aérea, trocas gasosas, Zea mays.

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Study in the Responses of-Some Soybean (Glycine max L.) Cultivars Under Water Stress Condition

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d040111 ◽

1970 ◽

Vol 4 (1) ◽

Author(s):

EDI PURWANTO

Keyword(s):

Glycine Max ◽

Water Stress ◽

Field Condition ◽

Growth Stages ◽

Soybean Cultivars ◽

Shoot Ratio ◽

Root Shoot Ratio ◽

Water Stress Condition ◽

Root And Shoot Length ◽

Glycine Max L

These sets of experiments were conducted at Faculty of Agriculture Sebelas Maret University and the Central Experiment Station of Agricultural Faculty, Sebelas Maret University at Jumantono, Karanganyar, Central Java. The experiments were conducted under greenhouse, laboratory and field condition for each year, while the duration of this research was for two years. The specific objectives of the experiments were: (i) to determine the changes of some morpho-physiological characteristics of water stress soybean and those of unstressed plants at different growth stages; (ii) to evaluate relationship between morpho-physiological traits associated with water stress resistance and yield of soybean. In this study consists some experiments, there are: (i) about response of some soybean cultivars to water stress in screen house and field condition; (ii) about germination response of some soybean cultivars in different concentration 0f PEG; (iii) a bout recovery survival and recovery of soybean seedlings after heat treatment. The plants were well watered before thetreatment. Based on the result of the experiments, the following conclusion could be made: (i) water stress reduced growth, yield and yield components 0 f a II soybean c ultivars used; (li) PEG induced water stress resulted in lower germination, shorter root and shoot length, and increase root-shoot ratio; (iii) the ability of plants to recovery after heat stress have low correlation with drought resistance in this experiment; (iv) the determination of root-shoot ratio in the seedling stage was shown to be suitable screening techniques used to study water stress resistance.Â© 200'3Jurusan Biologi FMIPA UNS SurakartaKey words: soybean (Glycine max L.), cultivars, water stress.

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MORPHOLOGICAL AND PHYSIOLOGICAL STUDY FOR SUGARCANE EARLY SELECTION TO DROUGHT TOLERANCE

PLANT ARCHIVES ◽

10.51470/plantarchives.2021.v21.no1.269 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

A. A. Gaber ◽

A. F. Abou-Hadid ◽

Y. A. El- Gabry ◽

M. H. M. Ebid

Keyword(s):

Water Stress ◽

Stress Condition ◽

Agricultural Research ◽

Water Levels ◽

Research Station ◽

Fresh Weight ◽

Shoot Fresh Weight ◽

Shoot Ratio ◽

Root Shoot Ratio ◽

Water Stress Condition

In Egyptian sugarcane breeding program, a pot experiment was carried out during 2019 season at Agricultural Research Station, Giza Governorate (latitude 26o 33? N and longitude 31o 12? E), Egypt, to evaluate twenty sugarcane clones, compared with the cultivated variety GT.54-9, under three irrigation water levels IWL (100, 80 and 60% of IWL). The traits FW of the shoot and root, root: shoot ratio, LAI, LAR, Chla, Chlb, Chla: Chlb ratio, carotenoids and proline were assessed. From this study clones 17 had height shoot fresh weight under water stress condition, as same as, clones 1, 18 and 19 had great behavior under water stress. In addition to most of sugarcane tested clones were not affected by increase the degree of water stress from 100 to 80% of IWL. The LAI, Chl.a and Chl.b traits showed the high correlation with shoot fresh weight, whereas, proline had strong relationships with root fresh weight under sugarcane drought stress.

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Effect of Water Stress Induced by PEG on Growth and Quality of Bunching Onion

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.142.116 ◽

2011 ◽

Vol 142 ◽

pp. 116-119

Author(s):

De Zhong Dong ◽

Hou Cheng Liu ◽

Shi Wei Song ◽

Guang Wen Sun ◽

Ri Yuan Chen

Keyword(s):

Water Stress ◽

Pyruvic Acid ◽

Allium Fistulosum ◽

Plant Weight ◽

Effect Of Water ◽

Shoot Ratio ◽

Root Shoot Ratio ◽

Total Plant ◽

Bunching Onion

The effect of water stress on growth and quality of bunching onion（Allium fistulosum L. var. caespitosum Makino）was studied in hydroponics by PEG treatments (10%, 15%, 20%). The results showed that the growth of bunching onion was significantly affected by water stress induced by PEG. Plant height, pseudo-stem weight, total plant weight decreased with PEG concentration increased, the inhibitions in 10% PEG and 20% PEG were greater than in 15% PEG. The root/shoot ratio increased in PEG treatments. Concentrations of allicin and pyruvic acid significantly increased at 10, 17 days after PEG treatments. With PEG concentration increased, concentrations of soluble protein increased.

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DROUGHT-TOLERANT MAIZE GENOTYPES INVEST IN ROOT SYSTEM AND MAINTAIN HIGH HARVEST INDEX DURING WATER STRESS

Revista Brasileira de Milho e Sorgo ◽

10.18512/1980-6477/rbms.v15n3p450-460 ◽

2016 ◽

Vol 15 (3) ◽

pp. 450 ◽

Cited By ~ 3

Author(s):

RONIEL GERALDO AVILA ◽

PAULO CESÁR MAGALHÃES ◽

AMAURI ALVES DE ALVARENGA ◽

ALYNE DE OLIVEIRA LAVINSKY ◽

CLEIDE NASCIMENTO CAMPOS ◽

...

Keyword(s):

Water Stress ◽

Root System ◽

Dry Weight ◽

Carbon Partitioning ◽

Drought Tolerant ◽

Shoot Ratio ◽

Root Shoot Ratio ◽

Maize Genotypes ◽

Female Flowering ◽

Source Sink

ABSTRACT – Drought is considered the primary limitation to agriculture and, can reduce grain yield by up to 60% when occurs at pre-flowering in maize. In this context this research, aimed to understand the maize genotypes behavior to drought management and carbon partitioning between grain production and structures to maintain hydration when submitted to drought. Maize genotypes tolerant (DKB390 and P30F35) and sensitive (BRS1010 and 2B710) to drought were grown in a greenhouse using two water conditions: irrigated and stressed. Water deficit was imposed at pre-flowering and maintained for twelve days. Leaf water potential, gaseous exchange and male and female flowering interval were evaluated. At the end of the cycle, production components and root/shoot ratio dry weight were evaluated. Drought-tolerant genotypes used root system as a mechanism of tolerance to drought, which ensure greater efficiency in absorption and loss of water and, consequently, greater stomatal conductance during the drought, compared to the sensitive-genotypes. In addition, drought-tolerant genotypes showed greater stability in the source-sink relationship, exhibiting higher photosynthetic rate and harvest index.Keywords: water stress, carbon partitioning; root/shoot ratio dry weight, gas exchanges, Zea mays.GENÓTIPOS DE MILHO TOLERANTES À SECA INVESTEM EM SISTEMA RADICULARE MANTEM ALTO ÍNDICE DE COLHEITA DURANTE O ESTRESSE HÍDRICORESUMO- A seca é considerada restrição primária à agricultura, e no milho, quando ocorre no pré-florescimento, pode reduzir o rendimento de grãos em até 60%. Neste contexto, objetivou-se entender como genótipos de milho contrastantes para tolerância à seca, gerenciam o particionamento de carbono entre produção de grãos e estruturas de manutenção da hidratação durante a seca. Para isso, em casa de vegetação cultivaram-se genótipos de milho tolerantes (DKB390 e P30F35) e sensíveis (BRS1010 e 2B710) à seca, em duas condições hídricas: irrigado normal e déficit hídrico. No pré-florecimento foi imposto o déficit hídrico, que foi mantido por doze dias. Posteriormente avaliou-se o potencial hídrico foliar, trocas gasosas e intervalo de florescimento masculino e feminino. No final do ciclo, avaliaram-se os componentes de produção e a razão raiz/parte aérea. Constatou-se que, genótipos tolerantes utilizaram preferencialmente sistema radicular como um mecanismo de tolerância à seca, o que garantiu a esses genótipos, maior eficiência entre a absorção e perda de água e, consequentemente, maior condutância estomática durante a seca, em relação aos genótipos sensíveis. Além disso, os genótipos tolerantes apresentaram maior equilíbrio em suas relações fonte e dreno, exibindo maiores taxa fotossintética e índice de colheita.Palavras-chave: estresse hídrico, particionamento de carbono, razão raiz/parte aérea, trocas gasosas, Zea mays.

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