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my-autism-adhd-blog · 8 months

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Hi everyone,

It’s been extremely hot this month, so I wanted to share some information about autism and heat intolerances. Here’s an excerpt from one article:

Beyond common medical conditions caused by extreme heat (e.g., exhaustion and heatstroke), individuals with autism often have sensory sensitivities affecting their ability to regulate temperature; their heat intolerance may be part of sensory difficulties. Our recent interviews with parents and professional care providers suggest, after exposure to high temperatures, children with autism are significantly more likely to have rapid and unstable mood shifts and present strong behavioural, emotional, and communication challenges. In addition, limited outdoor opportunities greatly affect children’s routines and space for daily activities, further intensifying their stress and anxiety.

The full article will be down below if you’d like to read more:

I found another article talking about heat tolerance. Here’s an excerpt from that article:

Autistic people face multiple challenges during heat waves. They may have difficulty understanding why they need to wear a hat, coat, or sunscreen. They may struggle with finding comfortable places to sit or lie down, and they may find it difficult to keep themselves cool and safe.

Some autistic people suffer from hyperthermia (overheating) and hypothermia (underheating). This means they don’t always respond well to changes in temperature. For example, some autistic people may become agitated when they get too warm. Others may become anxious when they get cold. If this happens, it could lead to sensory overload and an outburst.

Also, children on the autism spectrum are more easily triggered when dealing with hot weather. They may become very upset by the increased body temperature, which makes them less able to control their emotions. An autistic child may also be at greater risk of overheating because he has trouble regulating his own body temperature.

(I know this refers to children, but I think this could be applied to teenagers and adults).

This article from this excerpt will also be below if anyone wants to read through it:

I hope many of you find this helpful. Stay cool, hydrated, and safe.

Autism

Heat Tolerance

#autism #actually autistic #heatwave #heat tolerance #autism & heat #autism and health #physical health #stay hydrated #stay cool #be safe #feel free to share/reblog #tw bright colors #tw eye strain

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oaresearchpaper · 26 days

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Heat Tolerance and Early Flowering QTLs Validation in IR64 Rice

Abstract

Heat stress reduces rice yield by 10% for every degree Celsius increase beyond optimum temperature. Field testing of IR64-derived near-isogenic lines with heat tolerance and early morning flowering QTLs was conducted at CSU Piat during hottest months of 2016-2017. To evaluate how well IR64 NILs tolerated heat, morpho-agronomic data were collected and analyzed when they were subjected to high temperature at field conditions. Flower opening time (FOT), the peak flowering time (PFT), and the time when all of the flowers are closed (FCT) were also determined for early morning flowering traits (EMF). Results showed that morpho-agronomic features of IR64-derived NILs such panicle length, number of tillers per hill, spikelet fertility, spikelet/panicle, plant height, days to 50% flowering and maturity were similar when compared to its recurrent parent. Moreover, EMF traits results revealed that IR64HT+EMF and IR64EMF NILs exhibited the earliest FOT, PFT, and CFT. This research under high temperature field condition clearly validated the heat tolerance performance of IR64-derived NILs had similar morpho-agronomic traits compared to its recurrent parent indicating recovery of recurrent parent genome. Furthermore, IR64HT+EMF and IR64EMF NILs exhibited the earliest FOT, PFT, and CFT indicating that the presence of qEMF3 and its combination with qHTSF4.1 strongly confers EMF traits as an escape mechanism from heat stress. The researchers recommend the use of genetic materials with combined genes of heat tolerance (qHTSF4.1) and early morning flowering (qEMF3) for these are useful germplasm for future and expected global warming.

Introduction

In rice, temperature above optimum levels affects all growth stages. Among these, the flowering stage is considered the most sensitive stage to high temperature (Satake and Yoshida, 1978; Yoshida et al., 1981). Heat-induced spikelet sterility results if the sensitive physiological processes of anther dehiscence, pollination, pollen germination on the stigma, and pollen tube growth are aggravated (Wassmann et al., 2009a). In the study of Jagadish et al. (2007), sterility was induced for less than 30 minutes of exposure to 35°C ambient temperature and 33.7°C spikelet tissue temperature during anthesis. However when spikelets opened either before or for more than an hour after the onset and exposure of high temperature, they were unaffected by the heat treatment (Jagadish et al., 2007).

Flowering is the most sensitive stage to high temperature in the rice life cycle. High temperature of over 35°C at flowering stage increases pollen and spikelet sterility, which leads to significant yield losses, low grain quality, and low harvest index. Large cultivar variation exists in the spikelet sensitivity to high temperature damage, and the primary cause of this cultivar variation in high temperature (heat) tolerance at flowering is the number of viable pollen grains shed on the stigma, resulting from the changes in the extent of anther dehiscence, which directly affect the spikelet fertility and grain yield. Thus, spikelet fertility under high temperature has been widely used as a screening index for heat tolerance at reproductive stage.

Heat tolerance is the ability of the plant to grow, develop, and produce an economic yield under high temperature stress (Wahid et al., 2007; Paupiere et al., 2014). There are three basic mechanisms of heat tolerance in plants: (1) true heat tolerance, where plants can shed a large amount of pollen or viable pollen able to germinate under heat stress and (2) heat avoidance, where the plant performs its sensitive functions (ie. fertilization) before the onset of the stress (Yoshida et al., 1981; Ishimaru et al., 2010). The latter can be done by several ways: macroescape (heading during the cooler parts of the season), and microescape (anther dehiscence occurring during the cooler parts of the morning) (Wassmann et al., 2009a); and (3) heat escape, by changing leaf orientation, efficient transpirational cooling of the canopy, reduction in non-photosynthetic energy intercepted by the canopy, and reflection of solar radiation (Bahuguna et al., 2014).

Significant genotypic variation had also been found for time of day of flowering (TDF) and early morning flowering (EMF) or peak anthesis in rice germplasm. It has been reported that O. glaberrima is an EMF wild rice species with the ability to flower immediately after dawn, and with more than 90% of spikelets nearing anthesis by 0900H (Prasad et al., 2006). Interspecific crosses were made between O. glaberrima and O. sativa, which produced lines that had significantly earlier peak anthesis hours than the original parent (Yoshida et al., 1981). Ishimaru et al. (2010) successfully introgressed the EMF trait from another wild rice, O. officinalis into Koshihikari (O. sativa), and the produced Koshihikari + EMF line can open its spikelets 2 hours earlier than the Koshihikari wild type. This adaptation allowed the line to garner higher spikelet fertility than others popular varieties lacking the EMF trait. The produced EMF introgression line was used to develop near-isogenic lines of Nanjing 11 (temperate cultivar) and IR64 (tropical/subtropical cultivar) and successfully and stably exhibited the EMF trait (Hirabayashi et al., 2014).

Redoña et al. (2009) expressed that identifying the quantitative trait loci (QTL) for heat tolerance and employing marker-assisted selection (MAS) could compensate for the difficulty of field screening and significantly improve the overall efficiency of the breeding process. Genomic techniques and tools like MAS can ease selection of target traits, that can be used to (1) identify, quantify, and characterize genetic variation; (2) tag, clone, and introgress genes and/or QTL; and (3) manipulate (eg. pyramid, integrate) genetic variation in breeding populations (Xu and Crouch, 2008). Genetic mapping studies for EMF and heat-tolerant QTLs during the reproductive stage of different rice populations have been undertaken (Jagadish et al., 2008; Ishimaru et al., 2010; Jagadish et al., 2010a; Xiao et al., 2011; Ye et al., 2012; Hirabayashi et al., 2014; Ye et al., 2016). In the mapping study conducted by Ye et al. (2012), four major heat-tolerance QTLs were identified from the progeny of IR64 x N22 cross, to which N22 is the heat-tolerant variety. Of the four chromosomal locations identified, QTLsqHTSF1.1 (on chromosome 1 of IR 64) and qHTSF4.1 (on chromosome 4 of N22) were confirmed to have the most significant role for increasing spikelet fertility under high temperature (Ye et al., 2012) and were found to be very close to major QTLs identified in the studies of Jagadish et al. (2010a) and Xiao et al. (2011). Between the two QTLs, plants with the qHTSF4.1 exhibited higher spikelet fertility than other genotypes, and was also detected and confirmed by Ye, et al. (2016) in an IR64/Giza 178 bi-parental cross and IR64/Milyang/Giza 178 three-way cross, suggesting its potential significance in enhancing heat tolerance of rice during the flowering stage.

Some species of wild rice were found to flower early in the morning, such as O. glaberrima (A genome), O. rufipogon (A genome), and O. officinalis (C genome) (Yoshida et al., 1981; Ishimaru et al., 2010; Thanh et al., 2010). The group of Ishimaru et al. (2010) transferred the EMF trait from O. officinalis into the genetic background of O. sativa cv. Koshihikari, producing EMF20, an introgression line. The EMF20 was crossed with Nanjing 11. Using SSR markers, significant QTLs were identified on chromosome 3 (qEMF3) and chromosome 8 (qEMF8). Comparison of the recurrent parent and near-isogenic lines with the qEMF3 showed that the EMF20 allele of the QTL significantly advanced the flowering opening time (FOT) by 1.5-2.0 hours.

Developing near-isogenic lines (NILs) are advantageous in evaluating the effect of the QTLs on the phenotype (marker-trait association). Gene expression can change during morpho-physiological and reproductive development as well as when subjected to biotic and abiotic stresses. Validation of the function of the introgressed QTLs in NILs will allow breeders to optimize phenotypic selection procedures (Xu and Crouch, 2008).

This study aimed to determine the effect of QTLs for heat tolerance (qHTSF4.1), EMF trait (qEMF3) and a combination of the two QTLs, introduced into the background of IR64 (O. sativa) on (1) the floret morphophysiological responses when flowering is exposed to elevated temperatures; (2) agronomic characters, and (3) spikelet fertility and grain yield of the lines.

Source : Heat Tolerance and Early Flowering QTLs Validation in IR64 Rice | InformativeBD

#Early morning flowering #Heat tolerance #Heat stress #QTL analysis #Rice

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