Menopausal transition (premenopause) is the phase in the ageing process of women representing the transition from the reproductive stage of life to the non-reproductive stage. With improvements in average life expectancy, women live an increased proportion of their lives in the postmenopause. The consequences of oestrogen loss are the early symptoms (psychological and vasomotor), the genitourinary syndrome (intermediate), as well as postmenopausal osteoporosis with increased risk of fractures and cardiovascular diseases (late). The diagnosis of climacteric syndrome is based on typical clinical symptoms. Perimenopausal women should understand physiological changes occurring in menopausal transition. They should be encouraged to live a healthy lifestyle. Menopausal hormone therapy is indicated for relief of the acute symptoms of menopause and for treatment of urogenital atrophy. It should be administered in the lowest effective dose for the shortest period of time. The treatment should be initiated before the age of 60 years or within 10 years after menopause in order to decrease its risks. The benefit/risk profile needs to be individually re-assessed every year.
Environmental conditions contribute to a large percentage of wheat yield variability. This phenomenon is particularly true in rainfed environments and non-responsive soils to N. However, the effect of P application on wheat is unknown in the absence of N fertilizer application. This study was conducted from 2012 to 2019 in permanent beds established in 2005. Treatments were arranged in a split-plot design and consisted of superimposing three P treatments (foliar, banded and broadcast application) plus a check (0P) within each one of four preceding N treatments (applied from 2005 to 2009). Foliar P generally showed a greater response than granular P treatments even though the soil tests high P (>30 mg/kg). Precipitation estimated for two different growth intervals explained through regression procedures the Years' effect. Seasonal precipitation (224–407 mm) explained variation of relative yield, N harvest index (NHI) and P agronomic efficiency (AE). Reproductive stage precipitation (48–210 mm) explained soil N supply. In dry years, foliar P application improved predicted relative yield 14% and AE 155 kg grain/kg P compared to granular P treatments. Similarly, soil N supply increased 15 kg/ha in dry moisture conditions during the reproductive stage. The NHI consistently improved over the crop seasons. This improvement was relatively larger for 0 kg N/ha. On average, NHI increased from about 0.57 to 0.72%. Normalized difference vegetation index (NDVI) readings at the booting growth stage were negatively associated with NHI. Foliar P in this non-responsive soil to N showed the potential to replace granular P sources. However, the omission of granular P needs to be further studied to estimate the long-term effect on the soil P test.
ABSTRACT: Temperature affects plant development therefore phyllochron has been used as a predictor for developmental events to define the time for agricultural managing practices. This study aims to evaluate changes in phyllochron and thermal sum required for flowering by oat genotypes developed at different decades at three temperature regimes; the effect of high temperature on phytomere development; and identify the development stage at the moment of meristem transition to reproductive stage. Three environments were obtained by sowing in the fall, in the spring, and under constant temperature (17oC), always at inductive photoperiod. Despite changes in nominal values small differences were found among genotypes’ phyllochron. Adding specific optimal and maximum temperatures into the growing degree days’ calculation demonstrated phyllochron stability among environments. Plant cycle length and thermal sum correlated with the number of developed phytomeres. UFRGS 078030-2 plants flowered earlier, had a small number of phytomeres, and greater tolerance to elevated temperatures than the other genotypes. More recent genotypes transit to reproductive stage at an earlier Haun stage than older ones.
<p class="042abstractstekst">Roots play an important role in wheat grain yield, especially under drought stress conditions. To investigate root characteristics under drought stress conditions in bread wheat, 90 lines F10 obtained from the crossing (‘Yecora Rojo’ × ‘Chinese Spring’) randomly with the parents of the population were examined. The study was conducted in the form of a split-plot design with a randomized complete block base in three conditions including: 1. no stress, 2. application of drought stress at the beginning of the vegetative stage, and 3. application of drought stress at the beginning of the reproductive stage. The results showed, interaction between genotype and condition of drought was significant for all root-related traits, except shallow root dry mass, at the level of 1 % probability. The response of root-related traits to different types of drought stress was very complex. The longest root length, decrease for 13.3 % was during stress at the beginning of the vegetative stage in comparison to non-stress conditions, while the same trait increased for 4.9 % during stress at the beginning of the reproductive stage, comparison to non-stress conditions. The results of principal component analysis under non-stress conditions showed that by considering the distribution of genotypes compared to the first two components, genotypes can be identified that have more yield with the proper root condition and vice versa.</p>
AbstractHigh temperature elicits a well-conserved response called the unfolded protein response (UPR) to bring protein homeostasis in the endoplasmic reticulum (ER). Two key UPR regulators bZIP28 and bZIP60 have been shown to be essential for maintaining fertility under heat stress conditions in Arabidopsis, however, the function of transcriptional activator bZIP17, a paralog of bZIP28, in heat stress response at reproductive stage is not reported. Here we found that bzip17 mutant plants were sensitive to heat stress in terms of silique length and fertility comparing to that of wildtype (WT) Arabidopsis plants, and transcriptomic analysis showed that 1380 genes were specifically up-regulated and 493 genes were specifically down-regulated by heat stress in the flowers of WT plants comparing to that in bzip17 mutant plants. These bZIP17-dependent up-regulated genes were enriched in responses to abiotic stresses such as water deprivation and salt stress. Further chromatin immuno-precipitation coupled with high-throughput sequencing (ChIP-Seq) uncovered 1645 genes that were direct targets of bZIP17 in MYC-bZIP17 expressing seedlings subjected to heat stress. Among these 1645 genes, ERSE-II cis-element was enriched in the binding peaks of their promoters, and the up-regulation of 113 genes by heat stress in flowers was dependent on bZIP17. Our results revealed direct targets of bZIP17 in flowers during heat stress responses and demonstrated the important role of bZIP17 in maintaining fertility upon heat stress in plants.
Endophytic bacteria play potentially important roles in the processes of plant adaptation to the environment. Understanding the composition and dynamics of endophytic bacterial communities under heavy metal (HM) stress can reveal their impacts on host development and stress tolerance. In this study, we investigated root endophytic bacterial communities of different rice cultivars grown in a cadmium (Cd)-contaminated paddy field. These rice cultivars are classified into low (RBQ, 728B, and NX1B) and high (BB and S95B) levels of Cd-accumulating capacity. Our metagenomic analysis targeting 16S rRNA gene sequence data reveals that Proteobacteria, Firmicutes, Actinobacteria, Acidobacteria, Bacteroidetes, and Spirochaetes are predominant root endophytic bacterial phyla of the five rice cultivars that we studied. Principal coordinate analysis shows that the developmental stage of rice governs a larger source of variation in the bacterial communities compared to that of any specific rice cultivar or of the root Cd content. Endophytic bacterial communities during the reproductive stage of rice form a more highly interconnected network and exhibit higher operational taxonomic unit numbers, diversities, and abundance than those during the vegetative stage. Forty-five genera are significantly correlated with Cd content in rice root, notably including positive-correlating Geobacter and Haliangium; and negative-correlating Pseudomonas and Streptacidiphilus. Furthermore, Phylogenetic Investigation of Communities by Reconstruction of Unobserved States analysis shows that functional pathways, such as biosynthesis of siderophore and type II polyketide products, are significantly enhanced during the reproductive stage compared to those during the vegetative stage under Cd stress. The isolated endophytic bacteria from the Cd-contaminated rice roots display high Cd resistance and multiple traits that may promote plant growth, suggesting their potential application in alleviating HM stress on plants. This study describes in detail for the first time the assemblage of the bacterial endophytomes of rice roots under Cd stress and may provide insights into the interactions among endophytes, plants, and HM contamination.