Saussurea involucrata PIP2;7 improves photosynthesis and drought resistance by decreasing the stomatal density and increasing intracellular osmotic pressure

Abstract Drought is one of the most important environmental factors limiting plant growth and productivity. The molecular mechanisms underlying plant drought resistance are complex and not yet fully understood. Here, we show that the Arabidopsis MADS-box transcription factor AGL16 acts as a negative regulator in drought resistance by regulating stomatal density and movement. Loss-of-AGL16 mutants were more resistant to drought stress and had higher relative water content, which was attributed to lower leaf stomatal density and more sensitive stomatal closure due to higher leaf ABA levels compared with the wild type. AGL16-overexpressing lines displayed the opposite phenotypes. AGL16 is preferentially expressed in guard cells and down-regulated in response to drought stress. The expression of CYP707A3 and AAO3 in ABA metabolism and SDD1 in stomatal development was altered in agl16 and overexpression lines, making them potential targets of AGL16. Using chromatin immunoprecipitation, transient transactivation, yeast one-hybrid, and electrophoretic mobility shift assays, we demonstrated that AGL16 was able to bind the CArG motifs in the promoters of the CYP707A3, AAO3, and SDD1 and regulate their transcription, leading to altered leaf stomatal density and ABA levels. Taking our findings together, AGL16 acts as a negative regulator of drought resistance by modulating leaf stomatal density and ABA accumulation.

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Variability and Plasticity in Cuticular Transpiration and Leaf Permeability Allow Differentiation of Eucalyptus Clones at an Early Age

Forests ◽

10.3390/f11010009 ◽

2019 ◽

Vol 11 (1) ◽

pp. 9 ◽

Cited By ~ 2

Author(s):

André Carignato ◽

Javier Vázquez-Piqué ◽

Raúl Tapias ◽

Federico Ruiz ◽

Manuel Fernández

Keyword(s):

Water Stress ◽

Drought Resistance ◽

Stomatal Density ◽

Stomatal Closure ◽

Eucalyptus Grandis ◽

Leaf Traits ◽

Improvement Program ◽

Stomatal Control ◽

Cuticular Transpiration ◽

Eucalyptus Dunnii

Background and Objectives. Water stress is a major constraining factor of Eucalyptus plantations’ growth. Within a genetic improvement program, the selection of genotypes that improve drought resistance would help to improve productivity and to expand plantations. Leaf characteristics, among others, are important factors to consider when evaluating drought resistance evaluation, as well as the clone’s ability to modify leaf properties (e.g., stomatal density (d) and size, relative water content at the time of stomatal closure (RWCc), cuticular transpiration (Ec), specific leaf area (SLA)) according to growing conditions. Therefore, this study aimed at analyzing these properties in nursery plants of nine high-productivity Eucalyptus clones. Material and Methods: Five Eucalyptus globulus Labill. clones and four hybrids clones (Eucalyptus urophylla S.T. Blake × Eucalyptus grandis W. Hill ex Maiden, 12€; Eucalyptus urograndis × E. globulus, HE; Eucalyptus dunnii Maiden–E. grandis × E. globulus, HG; Eucalyptus saligna Sm. × Eucalyptus maidenii F. Muell., HI) were studied. Several parameters relating to the aforementioned leaf traits were evaluated for 2.5 years. Results: Significant differences in stomatal d and size, RWCc, Ec, and SLA among clones (p < 0.001) and according to the dates (p < 0.001) were obtained. Each clone varied seasonally the characteristics of its new developing leaves to acclimatize to the growth conditions. The pore opening surface potential (i.e., the stomatal d × size) did not affect transpiration rates with full open stomata, so the water transpired under these conditions might depend on other leaf factors. The clones HE, HG, and 12€ were the ones that differed the most from the drought resistant E. globulus control clone (C14). Those three clones showed lower leaf epidermis impermeability (HE, HG, 12€), higher SLA (12€, HG), and lower stomatal control under moderate water stress (HE, HG) not being, therefore, good candidates to be selected for drought resistance, at least for these measured traits. Conclusions: These parameters can be incorporated into genetic selection and breeding programs, especially Ec, SLA, RWCc, and stomatal control under moderate water stress.

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Effect of fertilizer nitrogen on drought resistance in Coffea arabica L.

The Journal of Agricultural Science ◽

10.1017/s0021859600056173 ◽

1978 ◽

Vol 90 (3) ◽

pp. 625-631 ◽

Cited By ~ 12

Author(s):

A. J. Tesha ◽

D. Kumar

Keyword(s):

Drought Resistance ◽

Coffea Arabica ◽

Water Saturation ◽

Stomatal Density ◽

Bound Water ◽

Water Saturation Deficit ◽

Saturation Deficit ◽

Fertilizer Nitrogen ◽

Coffee Beans ◽

Coffea Arabica L

SummaryWhen coffee trees have a good supply of nitrogen they are less affected by drought. Explanation and evidence are presented. Trees treated with extra nitrogen contained more adenosine triphosphate, aqueous protein and ‘bound water’.Such N-rich trees exhibited lower transpiration rates than trees relatively poor in N when water supply was limiting. They had lower stomatal density and water saturation deficit values. Leaves maintained higher chlorophyll and turgidity. The conclusion is that nitrogen increases the drought-resisting capacity of coffee trees. This aspect was clearly reflected in yield, as nitrogen-rich trees produced more coffee beans.

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MADS-box factor AGL16 negatively regulates drought resistance via stomatal density and stomatal movement

10.1101/723106 ◽

2019 ◽

Author(s):

Ping-Xia Zhao ◽

Zi-Qing Miao ◽

Jing Zhang ◽

Qian-Qian Liu ◽

Cheng-Bin Xiang

Keyword(s):

Drought Stress ◽

Drought Resistance ◽

Molecular Mechanisms ◽

Stomatal Density ◽

Stomatal Closure ◽

Negative Regulator ◽

Stomatal Development ◽

Mads Box ◽

Loss Of Function ◽

Research Attention

ABSTRACTDrought is one of the most severe environmental factors limiting plant growth and productivity. Plants respond to drought by closing stomata to reduce water loss. The molecular mechanisms underlying plant drought resistance are very complex and yet to be fully understood. While much research attention has been focused on the positive regulation of stomatal closure, less is known about its negative regulation, equally important in this reversible process. Here we show that the MADS-box transcriptional factor AGL16 acts as a negative regulator in drought resistance by regulating both stomatal density and movement. Loss-of-function mutantagl16was more resistant to drought stress with higher relative water content, which was attributed to a reduced leaf stomatal density and more sensitive stomatal closure due to a higher leaf ABA level compared with wild type, whileAGL16overexpression lines displayed the opposite phenotypes.AGL16is preferentially expressed in guard cells and down regulated in response to drought stress. The expression ofCYP707A3andAAO3in ABA metabolism andSDD1in stomatal development was altered by AGL16 as shown inagl16and overexpression lines. Chromatin immunoprecipitation, transient transactivation, and yeast-one-hybrid assays demonstrated that AGL16 bound the CArG motif in the promoter of theCYP707A3,AAO3, andSDD1to regulate their transcription, and therefore alter leaf stomatal density and ABA level. Taken together, AGL16 acts as a negative regulator of drought resistance by modulating leaf stomatal density and ABA accumulation.

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Overexpression of maize SDD1 (ZmSDD1) improves drought resistance in Zea mays L. by reducing stomatal density

Plant Cell Tissue and Organ Culture (PCTOC) ◽

10.1007/s11240-015-0757-8 ◽

2015 ◽

Vol 122 (1) ◽

pp. 147-159 ◽

Cited By ~ 24

Author(s):

Yanbo Liu ◽

Lijun Qin ◽

Lizhen Han ◽

Yang Xiang ◽

Degang Zhao

Keyword(s):

Zea Mays ◽

Drought Resistance ◽

Zea Mays L ◽

Stomatal Density

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Drought resistance of English roses varieties in the conditions of the Right-bank Forest-Steppe of Ukraine

Plant varieties studying and protection ◽

10.21498/2518-1017.17.1.2021.228212 ◽

2021 ◽

Vol 17 (1) ◽

pp. 60-65

Author(s):

D. S. Gordienko ◽

O. L. Rubtsova ◽

T. O. Buidina ◽

V. I. Chizhankova ◽

O. F. Rozhok ◽

...

Keyword(s):

Drought Resistance ◽

Urban Areas ◽

Unit Area ◽

Stomatal Density ◽

Forest Steppe ◽

Laboratory Studies ◽

National Academy Of Sciences ◽

The Right ◽

Academy Of Sciences ◽

Field And Laboratory Conditions

Purpose. To study the drought resistance of plants of English roses varieties. Methods. Field, anatomical, biometric. The drought resistance of plants in the field was assessed according to S. S. Pyatnitsky 6-point scale (1961). The number of stomata per unit area of the leaf blade was determined using a JSM-6700F scanning electron microscope (JEOL, Tokyo, Japan). Results. The drought resistance of plants of English rose varieties was investigated both in the field and laboratory conditions. According to visual observations, during periods with a low level of moisture supply, leaf turgor did not decrease; therefore, the field drought resistance of all varieties was estimated at 5 points. According to the parameters of stomatal density per unit of leaf area, varieties that have the maximum and minimum values of this indicator were identified. Conclusions. It was found that all studied varieties of English roses from the collection of the State Dendrological Park “Alexandria” of the National Academy of Sciences of Ukraine are quite drought-resistant in the field. But they differed significantly in the density of stomata per unit area. The largest average number of stomata per 0.5 mm2 (163.67±7.93 pcs.) was recorded in the variety ‘Alan Titchmarsh’, the lowest (47.67±1.94) – in ‘Charles Austin’. Comparison of data on leaf morphology of English roses and stomata density showed that varieties with smaller leaf sizes (‘Cottage Rose’, ‘Fisherman Friend’, ‘Noble Antony’, ‘Crocus Rose’) have a greater number of stomata per unit area, which indicates their high drought resistance. The data obtained from field and laboratory studies will be taken into account in the formation of recommendations on the use of roses for landscaping urban areas, where plants may find themselves in more extreme conditions than in an arboretum.

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Evaluation of the drought resistance of pea (Pisum sativum L.) from the VIR collection

PLANT BIOTECHNOLOGY AND BREEDING ◽

10.30901/2658-6266-2021-2-o1 ◽

2021 ◽

Author(s):

E. V. Semenova ◽

I. A. Kosareva

Keyword(s):

Drought Tolerance ◽

Osmotic Pressure ◽

Drought Resistance ◽

Early Stage ◽

Geographic Origin ◽

Field Tests ◽

Correlation Coefficients ◽

Pea Seedlings ◽

New Varieties ◽

Radicle Length

Background. As a result of global warming, climate change is now taking place, increasing the frequency and duration of droughts. Therefore, the development of new varieties with an increased drought resistance and adaptation to certain environmental conditions is of primary importance. The aim of this work was to modify the express method of drought resistance evaluation in peas at an early stage of plant growth and development, and to apply this method to test 50 accessions from the VIR global collection.Materials and methods. Drought resistance studies involved garden pea accessions of different eco-geographic origin, which had been previously characterized in field tests in conditions of the Krasnodar Territory in 2017-2019. The roll-ups protocol was used for evaluating early drought resistance in the accessions. The stress intensity was modified by varying the concentration of sucrose in the solution used for growing of pea seedlings. To select an appropriate concentration, an osmotic pressure of 0.5 and 0.7 MPa was applied. As a result, the osmotic pressure of 0.5 MPa was chosen. The diagnostic criterion of the method is the radicle length index (RLI), that is, the ratio of the average radicle length of seedlings against a provocative background to the control values.Results. The osmotically active solution led to significant reduction in the radicle length of pea seedlings. The studied accessions exhibited considerable genetic variability for early drought tolerance, the RLI value varied from 0.28 to 0.88. Sources of high drought resistance during the period of seedling growth have been identified. The correlation analysis showed the absence of a reliable relationship between the RLI and the crop structure indicators (correlation coefficients from r = +0.17 to r = -0.24).Conclusion. By using the method of determining the relative drought tolerance at early stages of pea accessions development, one highly resistant (k-9333 from Morocco) and 10 resistant accessions (k-1495, k-9372, k-9401, k-9418, k-9733, k-9909, k-9934, k-9938, k-10072, and k-10116.) have been identified.

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