The aim of this study was to evaluate the rat ovarian morphological and function changes after pinealectomy (px). Two months after px, young female Wistar rats were sacrificed and the right ovaries were analysed morphologically and the left ovaries were used for steroid receptor binding experiments. Blood was collected and steroid hormone and melatonin levels were measured using radioimmunoassay kits. Results revealed that in the px group the rat ovaries had an increase in the number of atretic follicles and interstitial cells. These cells showed hyperactivity features on transmission electron microscopy and morphometric analysis (p < 0.05 compared with control and sham groups). Px-group serum showed an increase in estradiol (p < 0.05) and a decrease in progesterone levels (p < 0.05) compared with other groups. Moreover, progesterone receptor expression was lower than control and sham groups (p < 0.05). We postulate that pinealectomy leads to many morphological alterations of rat ovaries that are associated with functional changes in steroidogenesis and a decrease in progesterone receptor expression.

We have demonstrated that cDNA array represents a powerful approach to identify key molecules in the estrogens therapy. A number of the candidates reported here should provide new markers that may contribute to the detection of target estrogen receptor. This information may also aid the development of new approaches to therapeutic intervention.

The chlorophyll a fluorescence parameters of four Phaseolus vulgaris L. genotypes were evaluated under drought in two greenhouse experiments. Under severe water stress, the thermotolerant genotype 'Diplomata' maintained significantly higher values of predawn leaf water potential (Ψw), maximum Fv/Fm and effective (ΦPSII) quantum yield of photosystem II , and non-photochemical quenching than 'Ouro Negro', in the first experiment, and 'A 285' and 'A 222', in the second one. Among these parameters, Fv/Fm showed more differences that discriminated between the genotype responses even when measured at night. Next, a difference between Fv/Fm after sundown and Fv/Fm at dawn on the same day (day ∆Fv/Fm), i.e., the intensity of photoinhibition, and a difference between Fv/Fm at dawn and Fv/Fm after sundown on the day before (night ∆Fv/Fm), i.e. the photoinhibition recovery, were evaluated. Day ∆Fv/Fm and night ∆Fv/Fm were significantly higher for 'Diplomata' under severe water stress in both experiments. In addition, 'Ouro Negro' in the first experiment and all the genotypes in the second showed negative values of night ∆Fv/Fm on the last day of drought when their Ψw were also minimal indicating no recovery from photoinhibition and the need for rehydration. At maturation, stressed plants of 'Diplomata' showed a significantly higher yield than 'Ouro Negro' in the first experiment and the same as 'A 285' in the second. Therefore, the thermotolerant genotype 'Diplomata' also showed drought tolerance, and the use of day ∆Fv/Fm and night ∆Fv/Fm fluorescence analysis was able to discriminate between the tolerances of these genotypes and to indicate the need for rehydration.

The objective of this study was to evaluate the effects of the application of contact herbicides recommended for common bean crops, as for chlorophyll a fluorescence parameters, leaf soluble proteins content (LSPC) and productivity. The experiment was conducted on the field with five treatments, which were the application of the following herbicides: bentazon (720 g ha-1), fluazifop-p-butil (187.5 g ha-1), fomesafen (250 g ha-1) fluazifop-p-butil + fomesafen (187.5 + 250 g ha-1), and a manually weeded control treatment without herbicide application, in a randomized block design with four replications. Bentazon was the only herbicide causing significant reductions, but only until the first day after herbicide application (DAA), on the following chlorophyll a fluorescence parameters: maximum quantum yield of photosystem II (Fv/Fm), effective quantum yield of photosystem II (ϕPSII), photochemical quenching (qP); it also induced an increase in non-photochemical quenching (NPQ). Fv/Fm was the best parameter to indicate herbicide effect on the photosynthetic apparatus of plants in the field. Chlorophyll a fluorescence parameters obtained in light-adapted leaves underwent a high environmental influence, especially deriving from the variation in the photosynthetic photon flow density (PPFD) during measurements; they are not recommended to evaluate the effects of herbicides on the field. None of the applied herbicides evaluated caused reductions in grain yield; therefore, they are recommended for common bean crops.

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