1. Water stress Fábia Guimarães Dias
Regulamento da absorção de água da raiz sob estresse abiótico condições
Mutante ou transgene dos alguns genes..
Fábia Guimarães Dias

2. Global warming Drought in the northeast state
increased
Rio Negro increased 30 meters this year
Drought in the northeast state

3. The importance of water
Water is a essential substance for plant life
It influences various functions in plants:
As structure, growth and metabolism.
 Corresponding 90% of the dry weight of many organs.
Como estrut
Water is a essential substance for plant life
It influences various functions in plants:
As structure, growth and metabolism.
 Corresponding 90% of the dry weight of many organs.

4. Infection by Pathogens
Stresses
Abiotic stress
Water
Drought
Flooding
Temperature
Cold
Freezing
High
Light
Low
Chemical/Soil
Salt or salinity
Mineral deficiency
Acid soil
Air pollutants
Elevated CO2
Biotic stress
Infection by Pathogens
virus, bacterias, fungi, nematodes and insects
Infection by Pathogens
virus, bacterias, fungi, nematodes e insects
Acid soil
Air pollutants
Ozone 1369
Sulfur dioxide 378
NOx oxide 2001
Elevated CO2

5. The number of publications per year related to abiotic stress

6. Drought
It is one of the most common limitations affecting the growth (causing metabolic changes)
It is one of the most common limitations affecting the growth and yield (causing metabolic changes, oxidative physiological)
Drought induces complex responses to adaptation of plants to limiting environments

7. Transcriptional regulatory network
ABA is a central regulator of plant responses
Estudar um pouco destas vias
desidratação celular em condições de água limitados induz um aumento nos níveis de ABA endógenos que desencadeiam alvo a jusante genes que codificam fatores de sinalização, fatores de transcrição, enzimas metabólicas, e outros [44]. no fase vegetativa, a expressão de genes responsivos ABA é principalmente regulada por fatores de transcrição bZIP (TFS) conhecido como AREB / Foros, que atuam em uma ABA responsiveelement- (ABRE) dependente [45-47]. ativação da ABA resultado cascatas de sinalização na tolerância das plantas maior ao stress desidratação. Em contraste, um dehydration responsive cis-acting elemento, seqüência DRE / CRT e seu DNA TFs ERF/AP2-type de ligação, e DREB1/CBF DREB2A, estão relacionados à desidratação ABA-independente e vias de temperatura resposta

8. Adaptation X acclimation
Plant adaptation:
Genetic resistance, acquired by the selection process for many generations
Plant acclimation:
Increased tolerance as a result of previous exposure to stress
Plant acclimation

9. Mechanisms of drought resistance
The mechanisms of drought resistance can be grouped into three categories:
Escape drought
Avoidance drought
Tolerate drought
Entretanto, as plantas usam mais de um mecanismo
de cada vez, para resistir a este tipo de estresse abiótico

10. Adaptation mechanisms
Escape drought
It is defined as the ability of a plant to complete their life cycle before the start of the drought period
This mechanism involves the rapid phenological development (early flowering and maturity) and plasticity (variation in duration of growth depending on the extent of the drought).
Avoidance drought
Ability of plants to maintain turgor and cell volume
By absorption of water by an abundant root system and reduce the loss by transpiration through stomatal closure.
Ability of plants to maintain turgor and cell volume, By absorption of water by an abundant root system and reduce the loss by transpiration through stomatal closure or by non-stomatal and cuticle

11. Adaptation mechanisms
Tolerate drought
It is a mechanism that allows the plant to keep the metabolism, even with the reduction of tissue water potential, mainly due to the accumulation osmolytes protein.
olerar à seca é um mecanismo que permite à planta manter o metabolismo, mesmo com a redução do potencial hídrico dos tecidos, devido principalmente ao acúmulo de solutos compatíveis ou osmólitos, proteinas osmoprotetoras e à capacidade antioxidante

12. Response of plant growth to stress
Response of plant growth to stress onset is often characterized by a rapid and acute (‘acute response’) inhibition, followed by recovery and adaptation to the new condition (‘adaptation response’)
Growth rate
adaptation
“acute”
Tempo
Inicio do estresse
In barley leaves, the leaf elongation rate decreased close to zero within seconds after salt addition to the roots, followed by recovery of LER to approximately 46% and 70% of the non-stressed plants within minutes and days, respectively
Do mesmo modo, no meristema apical

13. Response of plant growth to stress
While the acute response prepares plants for possibly more severe conditions, the adaptive response can be seen as the establishment of a new steady state to prolonged and stable stress.

14. Drought reduces leaf growth by affecting cell division and expansion
In dicotyledonous plant species, such as Arabidopsis, leaf growth results from the proliferation and subsequent expansion of founder cells, recruited from the SAM.
Initially leaf growth is driven exclusively by cell proliferation (P, red shading).
Within several days and starting from the leaf tip, cells exit the mitotic cell cycle and start to expand (E, green shading).
After a few days, leaf growth is steered solely by cell expansion. Again starting at the tip, cells become mature (no shading), coinciding with growth cessation
Leaf development
Time (day)
Folhas iniciam no flanco do meristema (SAM). O número de células recrutados podem influenciar o número de células final. Inicialmente o crescimento da folha é impulsionado exclusivamente por proliferação de células (P, sombreamento vermelho). Dentro de alguns dias e, a partir da ponta da folha, células sair do ciclo celular mitótico e começar a expandir (E, sombreamento verde). Depois de alguns dias, o crescimento da folha é guiada apenas pela expansão celular. Mais uma vez começando na ponta, as células se tornam maduros (sem sombreamento), coincidindo com a parada do crescimento [63]. O número de células final e tamanho pode, por conseguinte, dependem do comprimento das janelas de desenvolvimento de proliferação e de expansão (setas brancas e verde-claro), respectivamente, e / ou a duração do ciclo celular única (o mais curto ciclo, maior a célula a produção por unidade de tempo) e taxa de expansão.

15. The drought reduces leaf growth and affects cell division and expansion
The drought affects growth in Arabidopsis
Arabidopsis seedlings were germinated and grown on medium with or without mannitol up to 22 after stratification.
50% reduction in leaf sizer WT
25mM de manitol
Rolled and narrow leaves
Skirycz et al. 2010
Rolled and narrow leaves

16. The drought reduces leaf growth and affects cell division and expansion
Cellular changes during osmotic stress in Arabidopsis
Cellular measurements demonstrated that both reduction
in cell number and size contributed equally to
the reduced area of mature leaves grown on mannitol
(Fig. 2, A–C). Already at the first measurements at 9
DAS, both leaf size and cell number had significantly
decreased, while cell size was not affected by the
treatment (Fig. 2, A–C).
Não foi significativo em 9 DAS
Skirycz et al. 2010

17. Processes involved in regulating the growth of plants under drought
The chemical signals are transported via the xylem to the leaves, where they initiate numerous mechanisms of tolerance: avoid / tolerate
Della proteínas são reguladores negativos da resposta GA
Representação esquemática dos processos envolvidos na regulação do crescimento sobre a seca. Secagem do solo é detectado nas raízes ativando uma combinação de hidráulica e sinais químicos que são transportados através do xilema para as folhas, onde eles iniciam um número de mecanismos de tolerância. Resposta de maduro folhas pode ser descrito pelo modelo evitação / tolerância [1]. Em crescente tensão folhas leva a inibição do crescimento aguda seguida de adaptação crescimento tanto mediada por Della sinalização. O etileno promove DELLA estabilização e inibição do crescimento, enquanto ABA possivelmente está envolvida na recuperação do crescimento. ABA e etileno negativo cruzada foi demonstrada. Enquanto a sinalização hormonal é comum entre expansão (E) e proliferação (P) folhas, genes efetores são distintos. Nas folhas P, os inibidores de CDKA pode desempenhar um papel na resposta aguda, enquanto a respiração alternativa na adaptação de crescimento. em folhas em expansão, aperto da parede celular e mudanças na liderança da célula turgor a parada do crescimento, enquanto ajuste osmótico e afrouxamento da parede celular são importante para a adaptação de crescimento
Dry soil is detected in the roots by activating a combination of chemical signals and hydraulic

18. Leaf growth
The TFs regulating genes encoding enzymes in the catabolism of gibberellin (GA2ox) reducing the levels of GA, which stabilizes DELLA proteins, leading to inhibition of growth.
The gibberellin stimulates growth by inhibiting DELLA protein
o fitohormônio giberelina (GA) estimula o crescimento através da promoção a destruição de DELLAS
DELLA proteins are restricted to nuclear proliferation and cell expansion in plant

19. Leaf growth
The growth regulation mediated by DELLA proteins is conserved in different stresses and promotes a convergence between the classic stress hormones.
Della-mediada regulação do crescimento é conservada através de diferentes tensões [13, 36,38] e fornece uma ponto de convergência para os hormônios do estresse clássicos porque ABA, etileno, e jasmonato de sinalização todas positivamente afetar a estabilidade DELLA, principalmente através de alterações no GA concentrações

20. Flooding Stress

21. Main responses to flooding
What happen in flooded soil ?
Absence of O2 in the soil: Roots needs to breathe to grow
O2 available to the root is originally the soil pore spaces
Hypoxic (low oxygen)
o deslocamento e exclusão de oxigênio aéreo do solo, seqüestro de metabolicamente gases gerados no solo e
Anoxic (without oxygen)

22. Main responses to flooding
The flooding causes O2 deficiency, CO2 excess and excess ethylene
The O2 deficiency decreases the rate of aerobic respiration, which causes accumulation of metabolic toxins such as methane.
Quando a respiração aeróbica cessa nas raízes, os níveis de energia caem rapidamente,
reduzindo a absorção e transporte de íons

23. Main responses to flooding
The flooding can cause an immediate reduction in gas exchange between plant and environment
Affecting plant growth
Ends when the root aerobic respiration, energy levels drop quickly, reducing the absorption and transport of ions.
Planting sunflowers in flooding

24. Main responses to flooding
Seedlings of P. gonoacantha showed rapid growth under field capacity, while flooding reduced the growth roots and shoot
Piptadenia gonoacantha
Espécie arbórea da mata de galeria
avaliar o grau de tolerância à inundação, em diferentes níveis de luz, de plântulas de Piptadenia gonoacantha
A decomposição de
raízes está bastante relacionada com o aumento da
atividade fúngica nos solos inundados, bem como
à maior susceptibilidade das raízes aos
microorganismos hospedeiros
Hypotheses for the reduced growth of seedlings of P.gonoqchatha
a) Low production of ATP,
b) Decrease in the rate of CO2 assimilation due to stomatal closure,
c) Reduction in the synthesis and translocation of growth regulating substances such as gibberellins and cytokinins.
Ferreira et al (2001)

25. Main responses to flooding
Seedlings with two days of age grew up in sand completely flooded with water WT
Flooding
Os dados demonstraram que o alongamento da raiz hypcotyl inclusive foi suprimida por inundações (Fig. 1a, b). Além disso, da ecologização dos cotilédones também reprimida pela inundações. Além disso, supressão de antocianina acumulação na região do hipocótilo também foi observado, a supressão foi confirmada pela determinação antocianina (Fig. 1C). Estes efeitos visíveis foram observados a partir de 12 h de alagamento, indicando que a mudança substancial na transcrição ocorre nas plântulas de soja inundadas antes da 12 horas de tratamento.
The elongation of the hypocotyl was suppressed during the flooding
Nanjo et al 2011

26. Gene expression inducible by flooding
Expression of genes that encode small proteins in soybean
Of the 100 genes induced in the microarray analysis, only three showed fold change greater than 500 time
qPCR dos três genes
However, these genes
were defined as encoding unknown or hypothetical proteins,
and no further information was generated by several
bioinformatic analyses such as a pfam motif search
These genes encode unknown or hypothetical proteins

27. Gene expression in specific organs and tissues
All the organs were subjected to flooding during 6h
The three genes were
induced in all organs of 6 h flooded soybean seedlings
which are cotyledon, hypocotyl and root (Fig. 7a). In
contrast, genes encoding anthocyanin malonyltransferase
(MAT; Probe ID, GMFL01-28-O20-R), asparagine synthase
(ASNS; GMFL01-14-F20-R) and alpha-L-arabinofuranosidase
(ARAF; CX ) which identified as
flooding suppressible genes in microarray analysis (Supplementary
Table S1) were suppressed in all organs
(Fig. 7b).

28. How do plants tolerate flooding
Nénufar

29. Morphological adaptations
Aerenchyma is a specialization of the parenchyma.
Spaces filled with gas.
can induce morphological adaptations including the
formation of aerenchyma, cortical air spaces that allows
diffusion of air from shoot to root, and elongation of
adventitious roots, leaves and shoots through the induction
of cell wall loosening enzymes. These responses are closely
related with action of phytohormones such as ethylene,
abscisic acid and gibberellic acid (Bailey-Serres and Voesenek
2008).
Development of aerenchyma in the apical region of maize seedlings
Development of aerenchyma in roots of maize seedlings

30. Morphological adaptations
Negative geotropism