Postinvasive Bacterial Resistance Conferred by Open Stomata in Rice

Stomata are leaf pores that regulate gas exchange and water transpiration in response to environmental cues. They also function in innate immunity by limiting pathogen entry through actively closing in so-called stomatal defense. However, roles of stomata in plant disease resistance are not fully elucidated, especially in monocots. Here, we report that non–race specific resistance of the rice abscisic acid-deficient mutant Osaba1 to Xanthomonas oryzae pv. oryzae is due to increased stomatal conductance. Reducing stomatal conductance in the Osaba1 mutant increases its susceptibility to X. oryzae pv. oryzae. Artificial opening of stomata in wild-type plants leads to enhanced resistance to X. oryzae pv. oryzae. The rice mutant es1-1 with constitutively higher stomatal conductance exhibits strong resistance to X. oryzae pv. oryzae. Additionally, Osaba1 and es1-1 are resistant to X. oryzae pv. oryzicola. The data support that open stomata confer postinvasive resistance against bacterial pathogens in rice, and such resistance probably results from decreased leaf water potential. Our findings reveal a novel role of stomata in plant immunity through modulation of leaf water status, which provides physiological insight into the interactions between plant, pathogen, and environment.

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Effect of Water Stress on Stomatal Conductance and Leaf Water Relations of Leaves Along Current-Year Branches of Peach

Functional Plant Biology ◽

10.1071/pp9890549 ◽

1989 ◽

Vol 16 (6) ◽

pp. 549 ◽

Cited By ~ 4

Author(s):

SL Steinberg ◽

MJ Mcfarland ◽

JC Miller

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Water Potential ◽

Water Status ◽

Stomatal Closure ◽

Water Flux ◽

Leaf Water ◽

Leaf Water Status ◽

Mature Leaves ◽

Water Potentials

A gradation, that reflects the maturity of the leaves, exists in the leaf water, osmotic and turgor potential and stomatal conductance of leaves along current and 1-year-old branches of peach. Predawn leaf water potentials of immature folded leaves were approximately 0.24 MPa lower than mature leaves under both well-watered and dry conditions. During the daytime the leaf water potential of immature leaves reflected the water potential produced by water flux for transpiration. In well- watered trees, mature and immature unfolded leaves had a solute potential at least 0.5 MPa lower than immature folded leaves, resulting in a turgor potential that was approximately 0.8 MPa higher. The turgor requirement for growth appeared to be much less than that maintained in mature leaves. As water stress developed and leaf water potentials decreased, the osmotic potential of immature folded leaves declined to the level found in mature leaves, thus maintaining turgor. In contrast, mature leaves showed little evidence of turgor maintenance. Stomatal conductance was lower in immature leaves than in fully mature leaves. With the onset of water stress, conductance of mature leaves declined to a level near that of immature leaves. Loss of turgor in mature leaves may be a major factor in early stomatal closure. It was concluded that osmotic adjustment played a role in maintenance of a leaf water status favorable for some growth in water-stressed immature peach leaves.

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Midday stomatal conductance is more related to stem rather than leaf water status in subtropical deciduous and evergreen broadleaf trees

Plant Cell & Environment ◽

10.1111/j.1365-3040.2012.02563.x ◽

2012 ◽

Vol 36 (1) ◽

pp. 149-158 ◽

Cited By ~ 72

Author(s):

YONG-JIANG ZHANG ◽

FREDERICK C. MEINZER ◽

JIN-HUA QI ◽

GUILLERMO GOLDSTEIN ◽

KUN-FANG CAO

Keyword(s):

Stomatal Conductance ◽

Water Status ◽

Leaf Water ◽

Leaf Water Status

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Photosynthesis and Leaf Water, Carbohydrate, and Hormone Status during Rooting of Stem Cuttings of Acer rubrum

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.116.6.1052 ◽

1991 ◽

Vol 116 (6) ◽

pp. 1052-1057 ◽

Cited By ~ 13

Author(s):

T.J. Smalley ◽

M.A. Dirr ◽

A.M. Armitage ◽

B.W. Wood ◽

R.O. Teskey ◽

...

Keyword(s):

Stomatal Conductance ◽

Water Status ◽

Soluble Sugars ◽

Acer Rubrum ◽

Net Photosynthesis ◽

Zeatin Riboside ◽

Leaf Water ◽

Stem Cuttings ◽

Leaf Water Status ◽

Photosynthetic Rates

Leaf water status, carbohydrate levels, net photosynthesis, stomatal conductance, ABA, dihydrozeatin riboside (DHZR), and trans-zeatin riboside (ZR) levels were determined in a greenhouse during rooting of stem cuttings of Acer rubrum L. `Red Sunset' taken on 3 Sept. 1987 and 28 May 1988. Leaf water status deteriorated before rooting and improved after root emergence. Leaf carbohydrate concentrations (glucose, sucrose, total soluble sugars, and total carbohydrates) increased until rooting and decreased after rooting, while changes in starch concentrations were trendless. ABA levels increased after insertion of cuttings into the rooting medium, but decreased before rooting. No correlation between timing of rooting and concentrations of the cytokinins ZR or DHZR was observed. Photosynthetic rates during rooting were higher for the Sept. 1987 cuttings and did not decrease to the compensation point as did those for May 1988 cuttings. Low photosynthetic rates and stomatal conductance of the cuttings during rooting were associated with water stress. The relationship between photosynthetic rates of such cuttings and cytokinin (CK) or ABA content was unclear. Chemical names used: [S-(Z,E]-5-(1-hydroxy-2,6,6-trimethyl-4-oxo-2-cyclohexen-1-yl)-3-methyl-2, 4-pentadienoic acid (abscisic acid, ABA); 2-methyl-4-(1H-purin-6-ylamino)-2-buten-1-ol (zeatin, Z).

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Stomatal Responses and Whole-Tree Hydraulic Conductivity of Orchard Macadamia integrifolia Under Irrigated and Non-Irrigated Conditions

Functional Plant Biology ◽

10.1071/pp9910661 ◽

1991 ◽

Vol 18 (6) ◽

pp. 661 ◽

Cited By ~ 9

Author(s):

J Lloyd ◽

T Trochoulias ◽

R Ensbey

Keyword(s):

Stomatal Conductance ◽

Water Potential ◽

Leaf Water Potential ◽

Water Status ◽

Simple Expression ◽

Leaf Water ◽

Leaf Water Status ◽

Diurnal Patterns ◽

Macadamia Integrifolia ◽

Independent Variable

Diurnal patterns of stomatal conductance (gs) and leaf water potential (Ψ1) were determined for leaves on irrigated and non-irrigated 5-year-old Macadamia integrifolia trees over a 4-month period from September to December 1989. An empirical model for stomatal conductance was developed for irrigated trees using relationships to photon irradiance (I), leaf temperature (T1) and vapour mole fraction difference (D). This model accounted for 69% of the variance in gs, and was not improved by the inclusion of Ψ1 as an independent variable. Fitted parameters led to the effective prediction of gs for untried combinations of environmental variables. By using a simple expression to link leaf water potential to transpiration rate (E), the model was extended to prediction of Ψ1 from measurements of I, T1 and D. Stornatal conductances were significantly lower on non-irrigated trees after a 2-month dry period. Lower stornatal conductances were not accompanied by more negative Ψ1 indicating that soil rather than leaf water status may control gs in macadamia trees under non-irrigated conditions.

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PHYSIOLOGICAL AND PHENOLOGICAL VEGETATIVE RESPONSES OF Campomanesia adamantium (Cambess) O. Berg (Myrtaceae) TO THE HYDRIC SEASONALITY OF RUPESTRIAN FIELDS

Revista Árvore ◽

10.1590/0100-67622016000600002 ◽

2016 ◽

Vol 40 (6) ◽

pp. 973-981

Author(s):

Vinícius Coelho Kuster ◽

Mateus Scarpelli Aguiar Marcato de Paula ◽

Silvana Aparecida Barbosa de Castro ◽

Fernando Henrique Aguiar Vale

Keyword(s):

Stomatal Conductance ◽

Water Potential ◽

Water Availability ◽

Water Status ◽

Photosynthetic Performance ◽

Dry Season ◽

Leaf Water ◽

Leaf Water Status ◽

Rupestrian Fields ◽

Dry Seasons

ABSTRACT The rupestrian fields have two well-defined seasons throughout the year, with rainfall rates that reflect the rainy and dry seasons. This distinction in water availability affects the morphology, physiology and chemistry of plants, among other characteristics. Thus, it is aimed at evaluating the leaf water status, vegetative phenology and photosynthetic behavior of Campomanesia adamantium from a rupestrian field during the dry and rainy season. The study was conducted in Serra do Cipó, Minas Gerais, Brazil. From November 2011 to November 2012 it was examined vegetative phenophases and development of six individuals. Water potential, stomatal conductance, quantum yield and concentration of pigments were evaluated from four leaves of 3rd node per individual (n = 4-5) in the dry and rainy seasons. C. adamantium is an evergreen type and presents mature leaves and sprouting throughout the year. This species showed strategies that reduce water loss during the dry season in rupestrian field, such as decrease in stomatal conductance throughout the day, also associated with a reduction in leaf water potential. However, low water availability did not affect the photosynthetic performance, which enables the construction of new leaves and renovation of the crown even in dry periods. Finally, little reduction in the values of Fv/Fm throughout the day and increase the values of ΔF/Fm' in warmer times, both in the dry season, reiterates the ability of C. adamantium to adjust their physiology to seasonal water deficit of the rupestrian field.

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Employment of artificial neural networks for non-invasive estimation of leaf water status using color features: a case study in Spathiphyllum wallisii

Acta Physiologiae Plantarum ◽

10.1007/s11738-021-03244-y ◽

2021 ◽

Vol 43 (5) ◽

Author(s):

Amin Taheri-Garavand ◽

Abdolhossein Rezaei Nejad ◽

Dimitrios Fanourakis ◽

Soodabeh Fatahi ◽

Masoumeh Ahmadi Majd

Keyword(s):

Neural Networks ◽

Artificial Neural Networks ◽

Water Status ◽

Leaf Water ◽

Leaf Water Status ◽

Non Invasive ◽

Color Features ◽

Artificial Neural

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Visual estimation of plant water status in cereals

The Journal of Agricultural Science ◽

10.1017/s0021859600060524 ◽

1979 ◽

Vol 92 (1) ◽

pp. 83-89 ◽

Cited By ~ 13

Author(s):

H. G. Jones

Keyword(s):

Spring Wheat ◽

Water Status ◽

Plant Morphology ◽

Leaf Water ◽

Plant Water Status ◽

Plant Water ◽

Visual Estimation ◽

Leaf Water Status ◽

Visual Scoring ◽

Breeding Programmes

SummaryThe potential offered for plant breeding programmes by visual scoring techniques for plant water status was investigated in rice and spring wheat. It was found that differing plant morphology could seriously bias visual estimates of leaf water potential, particularly in spring wheat. In spite of this problem, it was found that at least for rice, this type of approach may have potential in future breeding programmes where an estimate of leaf water status is required, such as those for drought tolerance, so long as a high intensity of selection is not necessary.

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