Name: XISMENIA SOARES DA SILVA GASPARINI
Type: PhD thesis
Publication date: 06/11/2019
Advisor:

Name	Role
Geraldo Rogério Faustini Cuzzuol	Advisor *
Paulo Cezar Cavatte	Co-advisor *

Examining board:

Name	Role
Camilla Rozindo Dias Milanez	Internal Examiner *
Geraldo Rogério Faustini Cuzzuol	Advisor *
Gloria Maria de Farias Viégas Aquije	External Examiner *
LEONARDO VALANDRO ZANETTI	External Alternate *
MARCOS THIAGO GAUDIO GOMES	External Examiner *
Paulo Cezar Cavatte	Internal Examiner *
Silvia Tamie Matsumoto	Internal Alternate *

Summary: Paubrasilia echinata is a tree species originating from the Atlantic Forest. This
species has different morphotypes, among them the small and medium that
differ in morphology and ecological habit. The small morphotype is described
as an ombrophilous plant, while the medium morphotype shows heliophilic
behavior. From the climate reports released, it is noted that environmental
disturbances may occur as a result of these changes. According to reports, for
the northeast portion of the Atlantic Forest is expected intense warming and
reduction of rainfall. For the south / southeast portion, trends indicate warmer
weather, with intensification in rainfall patterns. The objective of this study was
to evaluate the combined effect of vapor pressure deficit (DPV) and
temperature on carbon allocation, as well as non-enzymatic antioxidant
responses (flavonoids, phenols and MDA) as mechanisms of tolerance to
these climate changes. Therefore, plants of small and medium morphotypes
were submitted to four different controlled environments (A), being A1- low
DPV and temperature (0.7 KPa and 25.9 ° C); A2- low DPV and high
temperature (31.6 ° C and 1.0 KPa); A3- high DPV and temperature (32.6 ° C
and 3.1 KPa) and A4- high DPV and temperature (26 ° C and 1.7 KPa). The
analysis of soluble sugars (AS), sucrose, reducing sugars (AR), starch and
wall polymers (cellulose, hemicellulose and lignin) were performed in the three
organs (leaf, stem and root) of plants of both morphotypes. Already the
analyzes referring to the non- enzymatic oxidant system were performed in
the leaves. Both morphotypes showed, in the A3 environment, higher
concentration of leaf AS in relation to the stem and root. This result presented
higher RA concentration and lower leaf sucrose concentration, since this
carbohydrate can be used as osmoregulator, besides being the main
translucent photoassimilate in plants and can be used in other reactions. The
roots of the small morphotype, under elevated temperature, presented higher
root concentration of sucrose compared to the other environments. In both
morphotypes, the RA concentration was higher in leaves, especially in A3.
Under high DPV, especially in A3, the small morphotype showed higher root
starch concentration and lower leaf concentration. In the mean morphotype,starch allocation was higher in leaves than in other organs. The highest
starch concentration is related to storage organs (seeds, tubers, roots ...)
and its lower leaf concentration is related to stress conditions. The high
concentration of lignin in the roots of both morphotypes may favor water
transport, besides protecting plant tissues from chemical / biological
degradation. The highest concentration of cellulose and hemicellulose was
observed in the medium morphotype A1 stems, and the opposite for the small
morphotype. Regarding the oxidative reaction, the small morphotype
presented higher content of H2O2 in A4, WHERE the lipid peroxidation,
indicated by the higher MDA content, was higher. The same result was
observed for the average morphotype in A1. Under these conditions, the nonenzymatic antioxidant system was inefficient due to the lower concentrations
of phenols and flavonoids. In higher temperature environment, the small
morphotype (A2) and the medium morphotype (A3) presented lower
concentration of H2O2 and MDA. This result may suggest less cellular
damage due to lower lipid peroxidation. Thus, it can be concluded that A1 and
A4 appear to be stressful conditions for the small and medium morphotype,
respectively. However A2 and A3 can be considered favorable environments,
respectively, for the small and medium morphotypes.
Keywords Brazil wood. DPV. Temperature. Carbohydrates - ERO's

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