scholarly journals Gibberellin in tomato: metabolism, signaling and role in drought responses

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Hagai Shohat ◽  
Natanella Illouz Eliaz ◽  
David Weiss
Keyword(s):  
Tomato Plant ◽  
Plant Response ◽  
Water Deficiency ◽  
Drought Avoidance ◽  
Drought Tolerant ◽  
Improved Performance ◽  
Plant Life Cycle ◽  
Response To Water ◽  
Signaling Components

AbstractThe growth-promoting hormone gibberellin (GA) regulates numerous developmental processes throughout the plant life cycle. It also affects plant response to biotic and abiotic stresses. GA metabolism and signaling in tomato (Solanum lycopersicum) have been studied in the last three decades and major components of the pathways were characterized. These include major biosynthesis and catabolism enzymes and signaling components, such as the three GA receptors GIBBERELLIN INSENSITIVE DWARF 1 (GID1) and DELLA protein PROCERA (PRO), the central response suppressor. The role of these components in tomato plant development and response to the environment have been investigated. Cultivated tomato, similar to many other crop plants, are susceptible to water deficiency. Numerous studies on tomato response to drought have been conducted, including the possible role of GA in tomato drought resistance. Most studies showed that reduced levels or activity of GA improves drought tolerance and drought avoidance. This review aims to provide an overview on GA biosynthesis and signaling in tomato, how drought affects these pathways and how changes in GA activity affect tomato plant response to water deficiency. It also presents the potential of using the GA pathway to generate drought-tolerant tomato plants with improved performance under both irrigation and water-limited conditions.

scholarly journals Inhibition of gibberellin accumulation by water deficiency promotes fast and long-term ‘drought avoidance’ responses in tomato

2021 ◽  
Author(s):  
Hagai Shohat ◽  
Hadar Cheriker ◽  
Himabindu Vasuki ◽  
Natanella Illouz-Eliaz ◽  
Shula Blum ◽  
...  
Keyword(s):  
Stomatal Closure ◽  
Leaf Size ◽  
Guard Cells ◽  
Primary Role ◽  
Water Deficiency ◽  
Drought Avoidance ◽  
Canopy Area ◽  
Responsive Element ◽  
Response To Water

ABSTRACTPlants reduce transpiration to avoid dehydration during drought episodes by stomatal closure and inhibition of canopy growth. While abscisic acid (ABA) has a primary role in ‘drought avoidance’, previous studies suggest that gibberellin (GA), might also be involved. Here we show in tomato (Solanum lycopersicum) that shortage of water inhibited the expression of the GA biosynthesis genes GA20 oxidase1 (GA20ox1) and GA20ox2 and induced the GA-deactivating gene GA2ox7 in leaves and guard cells, resulting in reduced bioactive GA levels. Drought regulation of GA metabolism was mediated by ABA-dependent and independent pathways, and by the transcription factor DEHYDRATION RESPONSIVE ELEMENT BINDING (DREB), TINY1. Mutations in GA20ox1 and GA20ox2 reduced water loss due to the smaller canopy area. On the other hand, loss of GA2ox7 did not affect leaf size, but attenuated stomatal response to water deficiency; during soil dehydration, ga2ox7 plants closed their stomata and reduced transpiration later than WT, suggesting that ga2ox7 stomata are hyposensitive to soil dehydration. Together, the results suggest that drought-induced GA deactivation in guard cells contributes to stomatal closure at the early stages of soil dehydration, whereas inhibition of GA synthesis in leaves promotes mainly the long-term reduction in canopy growth to reduce transpiration area.

scholarly journals Crosstalk of the Brassinosteroid Signalosome with Phytohormonal and Stress Signaling Components Maintains a Balance between the Processes of Growth and Stress Tolerance

2018 ◽  
Vol 19 (9) ◽  
pp. 2675 ◽  
Author(s):  
Damian Gruszka
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Regulatory System ◽  
Negative Regulator ◽  
Signaling Proteins ◽  
Signaling Crosstalk ◽  
Molecular Approaches ◽  
Plant Life Cycle ◽  
Signaling Components

Brassinosteroids (BRs) are a class of phytohormones, which regulate various processes during plant life cycle. Intensive studies conducted with genetic, physiological and molecular approaches allowed identification of various components participating in the BR signaling—from the ligand perception, through cytoplasmic signal transduction, up to the BR-dependent gene expression, which is regulated by transcription factors and chromatin modifying enzymes. The identification of new components of the BR signaling is an ongoing process, however an emerging view of the BR signalosome indicates that this process is interconnected at various stages with other metabolic pathways. The signaling crosstalk is mediated by the BR signaling proteins, which function as components of the transmembrane BR receptor, by a cytoplasmic kinase playing a role of the major negative regulator of the BR signaling, and by the transcription factors, which regulate the BR-dependent gene expression and form a complicated regulatory system. This molecular network of interdependencies allows a balance in homeostasis of various phytohormones to be maintained. Moreover, the components of the BR signalosome interact with factors regulating plant reactions to environmental cues and stress conditions. This intricate network of interactions enables a rapid adaptation of plant metabolism to constantly changing environmental conditions.

scholarly journals ABA AND STOMATAL RESPONSES IN TEPARY AND COMMON BEAN

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 682b-682
Author(s):  
Maria G. Janssen ◽  
Albert H. Markhart
Keyword(s):  
Common Bean ◽  
Xylem Sap ◽  
Drought Tolerant ◽  
Detached Leaves ◽  
Stomatal Sensitivity ◽  
Root Signal ◽  
Response To Water ◽  
Aba Content ◽  
The Relationship

Tepary beans (Phaseolus acutifolius Gray) are more drought tolerant and have stomata that are more sensitive to low leaf water potentials (ψ w) than common beans (P. vulgaris L.). This study was designed to examine the role of ABA in controlling stomatal behaviour in these species. Comparison of the bulk leaf ABA content does not explain why tepary stomata are more sensitive to low leaf ψ w compared to common bean (at -1.4 MPa ABA content increased 40-fold in common bean and 25-fold in tepary). We hypothesize that the greater sensitivity of tepary stomata to low leaf ψ w is related to a higher concentration of ABA in the xylem sap, and/or to a greater sensitivity of tepary stomata to ABA. Xylem sap of well-watered and water stressed plants is analyzed to determine the concentration of ABA, and whether ABA is a putative candidate serving as a chemical root signal in response to water stress in Phaseolus. To test stomatal sensitivity to ABA, epidermal strips and detached leaves are exposed to a range of ABA concentrations. The relationship between stomatal aperture and different ABA concentrations is discussed.

Can systems integration lead to improved performance? The role of strategic alliances

2021 ◽  
Vol 95 ◽  
pp. 17-28
Author(s):  
José-Mauricio Galli Geleilate ◽  
Ronaldo C. Parente ◽  
M. Berk Talay
Keyword(s):  
Strategic Alliances ◽  
Systems Integration ◽  
Improved Performance

Relationships between physiological traits and productivity of sugarcane in response to water deficit

2012 ◽  
Vol 152 (1) ◽  
pp. 104-118 ◽  
Author(s):  
M. DE A. SILVA ◽  
J. L. JIFON ◽  
J. A. G. DA SILVA ◽  
C. M. DOS SANTOS ◽  
V. SHARMA
Keyword(s):  
Water Deficit ◽  
Field Studies ◽  
Water Deficit Stress ◽  
Chlorophyll Contents ◽  
Physiological Variables ◽  
Drought Tolerant ◽  
Relative Water ◽  
Leaf Relative Water Content ◽  
Sugarcane Productivity ◽  
Response To Water

SUMMARYThe relationships between physiological variables and sugarcane productivity under water deficit conditions were investigated in field studies during 2005 and 2006 in Weslaco, Texas, USA. A total of 78 genotypes and two commercial varieties were studied, one of which was drought-tolerant (TCP93-4245) and the other drought-sensitive (TCP87-3388). All genotypes were subjected to two irrigation regimes: a control well-watered treatment (wet) and a moderate water-deficit stress (dry) treatment for a period of 90 days. Maximum quantum efficiency of photosystem II (Fv/Fm), estimated chlorophyll content (SPAD index), leaf temperature (LT), leaf relative water content (RWC) and productivity were measured. The productivity of all genotypes was, on average, affected negatively; however, certain genotypes did not suffer significant reduction. Under water deficit, the productivity of the genotypes was positively and significantly correlated with Fv/Fm, SPAD index and RWC, while LT had a negative correlation. These findings suggest that genotypes exhibiting traits of high RWC values, high chlorophyll contents and high photosynthetic radiation use efficiency under low moisture availability should be targeted for selection and variety development in programmes aimed at improving sugarcane for drought prone environments.

scholarly journals Here, there and everywhere – the importance of neutral lipids in plant growth and development

2021 ◽  
Author(s):  
Agnieszka Zienkiewicz ◽  
Marta Saldat ◽  
Krzysztof Zienkiewicz
Keyword(s):  
Life Cycle ◽  
Neutral Lipids ◽  
Single Layer ◽  
Pollen Grains ◽  
Dynamic Nature ◽  
Plant Life ◽  
Plant Environment ◽  
Plant Life Cycle ◽  
Diverse Plant

In plants, lipids serve as one of the major and vital cellular constituents. Neutral lipids reserves play an essential role in the plant life cycle by providing carbon and energy equivalents for periods of active metabolism. The most common form of lipid storage are triacylglycerols (TAGs) packed into specialized organelles called lipid droplets (LDs). They have been observed in diverse plant organs and tissues, like oil seeds or pollen grains. LDs consist of a core, composed mostly of TAGs, enclosed by a single layer of phospholipids that is decorated by a unique set of structural proteins. Moreover, the recent advances in exploration of LDs proteome revealed a plethora of diverse proteins interacting with LDs. This is likely the result of a highly dynamic nature of these organelles and their involvement in many diverse aspect of cellular metabolism, tightly synchronized with plant developmental programs and directly related to plant-environment interactions. In this review we summarize and discuss the current progress in understanding the role of LDs and their cargo during plants life cycle, with a special emphasis on developmental aspects.

Jun mediates Frizzled-induced R3/R4 cell fate distinction and planar polarity determination in the Drosophila eye

Development ◽  
2000 ◽  
Vol 127 (16) ◽  
pp. 3619-3629 ◽  
Author(s):  
U. Weber ◽  
N. Paricio ◽  
M. Mlodzik
Keyword(s):  
Cell Fate ◽  
Genetic Interaction ◽  
Function Analysis ◽  
Loss Of Function ◽  
Planar Polarity ◽  
Jnk Signaling ◽  
Drosophila Eye ◽  
Polarity Determination ◽  
Signaling Components

Jun acts as a signal-regulated transcription factor in many cellular decisions, ranging from stress response to proliferation control and cell fate induction. Genetic interaction studies have suggested that Jun and JNK signaling are involved in Frizzled (Fz)-mediated planar polarity generation in the Drosophila eye. However, simple loss-of-function analysis of JNK signaling components did not show comparable planar polarity defects. To address the role of Jun and JNK in Fz signaling, we have used a combination of loss- and gain-of-function studies. Like Fz, Jun affects the bias between the R3/R4 photoreceptor pair that is critical for ommatidial polarity establishment. Detailed analysis of jun(−) clones reveals defects in R3 induction and planar polarity determination, whereas gain of Jun function induces the R3 fate and associated polarity phenotypes. We find also that affecting the levels of JNK signaling by either reduction or overexpression leads to planar polarity defects. Similarly, hypomorphic allelic combinations and overexpression of the negative JNK regulator Puckered causes planar polarity eye phenotypes, establishing that JNK acts in planar polarity signaling. The observation that Dl transcription in the early R3/R4 precursor cells is deregulated by Jun or Hep/JNKK activation, reminiscent of the effects seen with Fz overexpression, suggests that Jun is one of the transcription factors that mediates the effects of fz in planar polarity generation.

Особенности концентрационного влияния гидротермального нанокремнезема при предпосевной обработке семян растений на показатели биомассы и высоты ростков при проращивании в темноте

2021 ◽  
Vol 14 (1) ◽  
pp. 44-60
Author(s):  
В.Н. Зеленков ◽  
В.В. Латушкин ◽  
В.В. Потапов ◽  
В.В. Карпачев ◽  
В.М. Косолапов ◽  
...  
Keyword(s):  
Seed Germination ◽  
Essential Role ◽  
Plant Response ◽  
Epigenetic Factors ◽  
Agricultural Plants

В работе представлены результаты скрининговых исследований 14 сельскохозяйственных растений с отличающимися биологическими и хозяйственно-полезными свойствами (17 генотипов, включая разные виды, сорта и гибриды) по оценке влияния гидротермального нанокремнезема на биомассу и высоту ростков при темновом проращивании. Выявлено четыре основных типа отклика (реакции) растений в изученном диапазоне концентраций (0,05; 0,01; 0,005; 0,001 и 0,0005%). Данные закономерности характерны как для показателя биомассы ростков, так и их высоты. Отмечена существенная роль генетического и эпигенетического факторов в формировании отзывчивости растений на применение гидротермального нанокремнезема при проращивании семян. The research presents the results of screening studies of 14 agricultural plants with different biological and useful economic properties (17 genotypes, including different species, varieties, and hybrids) to assess the effect of hydrothermal nanosilica on biomass and sprout height in the dark growth germination. Four main types of plant response were revealed in the studied concentration range (0.05, 0.01, 0.005, 0.001 and 0.0005%). These dependencies are characteristic both of the biomass sprout indicator and of the sprout height. The essential role of genetic and epigenetic factors in the formation of the plant response when using hydrothermal nanosilica in seed germination is pointed out.

Multimedia Use in UAE Education Context

2013 ◽  
pp. 80-92
Author(s):  
Salam Omar Ali ◽  
Fayez Albadri
Keyword(s):  
United Arab Emirates ◽  
Technology Use ◽  
Interactive Technology ◽  
Learning Objectives ◽  
The Other ◽  
Teachers And Students ◽  
Multimedia Technologies ◽  
Improved Performance ◽  
Interesting Learning

The growth in use of multimedia in United Arab Emirates schools has accelerated in recent years. Multimedia can be useful for both teachers and students alike. For example, multimedia is viewed as an important source of educational aids and a generator of resources that can add a lot to their performance. On the other hand, multimedia is positively perceived, for it makes the learning processes more comfortable and more enjoyable that leads to an improved performance. Generally, children are excited and fascinated by technology, and they are more receptive to lessons that are aided by multimedia. This is perhaps why many teachers are using multimedia in their classes to accomplish their learning objectives by creating a more interesting learning environment. For educators, multimedia provides a golden opportunity to promote interactive, technology-based collaborative learning that is perceived positively by all parties involved. This chapter investigated the role of the multimedia technologies in enhancing students’ performance as many studies showed that technology has a great effect on improving students’ reading, writing, and other skills. The study is also aimed at increasing educators’ awareness of the importance of multimedia technology use in classrooms.

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