ABA Mediates Plant Development and Abiotic Stress via Alternative Splicing.

Alternative splicing (AS) exists in eukaryotes to increase the complexity and adaptability of systems under biophysiological conditions by increasing transcriptional and protein diversity. As a classic hormone, abscisic acid (ABA) can effectively control plant growth, improve stress resistance, and promote dormancy. At the transcriptional level, ABA helps plants respond to the outside world by regulating transcription factors through signal transduction pathways to regulate gene expression. However, at the post-transcriptional level, the mechanism by which ABA can regulate plant biological processes by mediating alternative splicing is not well understood. Therefore, this paper briefly introduces the mechanism of ABA-induced alternative splicing and the role of ABA mediating AS in plant response to the environment and its own growth.

Population Genetic Analysis of Puccinia striiformis f. sp. tritici Suggests Two Distinct Populations in Tibet and the Other Regions of China.

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is an important disease on wheat, seriously threatening wheat production worldwide. China is one of the largest stripe rust epidemic regions in the world. The pathogen sexual reproduction and migration routes between Tibet and the other regions in China are still unknown. In this study, we obtained 961 Pst isolates from 1,391 wheat leaf samples from Gansu (277), Shaanxi (253), Sichuan (172), and Tibet (259), comprising 13 natural populations, and genotyped them with simple sequence repeat (SSR) markers. The isolates can be divided into two distinct clusters based on DAPC and STRUCTURE analyses. The genetic diversity of Longnan (in Gansu) and Yibin (in Sichuan) populations was the highest and lowest among the 13 populations, respectively. The hypothesis of multilocus linkage disequilibrium was rejected for the populations from Linzhi in the Himalayan, Longnan, Hanzhong, Guangyuan, Mianyang, Liangshan, and Chendu in the south Qinling Mountains at the level of P = 0.01, which indicated significant linkage among markers in these populations. Populations in the other regions had extensive gene exchange (Nm > 4); little gene exchange was found between Tibet and the other regions (Nm < 1). The results suggest that the Tibet epidemic region of Pst is highly differentiated from the other epidemic regions in China.

Multiple forms of vitamin B6 regulate salt tolerance by balancing ROS and abscisic acid levels in maize root.

Salt stress causes osmotic stress, ion toxicity and oxidative stress, inducing the accumulation of abscisic acid (ABA) and excessive reactive oxygen species (ROS) production, which further damage cell structure and inhibit the development of roots in plants. Previous study showed that vitamin B6 (VB6) plays a role in plant responses to salt stress, however, the regulatory relationship between ROS, VB6 and ABA under salt stress remains unclear yet in plants. In our study, we found that salt stress-induced ABA accumulation requires ROS production, in addition, salt stress also promoted VB6 (including pyridoxamine (PM), pyridoxal (PL), pyridoxine (PN), and pyridoxal 5'-phosphate (PLP)) accumulation, which involved in ROS scavenging and ABA biosynthesis. Furthermore, VB6-deficient maize mutant small kernel2 (smk2) heterozygous is more susceptible to salt stress, and which failed to scavenge excessive ROS effectively or induce ABA accumulation in maize root under salt stress, interestingly, which can be restored by exogenous PN and PLP, respectively. According to these results, we proposed that PN and PLP play an essential role in balancing ROS and ABA levels under salt stress, respectively, it laid a foundation for VB6 to be better applied in crop salt resistance than ABA.

Spermidine Enhanced Free Polyamine Levels and Expression of Polyamine Biosynthesis Enzyme Gene in Rice Spikelets under Heat Tolerance before Heading.

High temperatures (HT) before heading strongly inhibit the development of spikelets in rice. Spermidine (Spd) can improve rice's resistance to HT stress; however, the mechanism underlying this effect has not been elucidated. This study investigated several parameters, including yield, superoxide anion (O2.-), protective enzyme activities, and polyamine content, in a heat-sensitive genotype, Shuanggui 1. The yield and yield components decreased dramatically when subjected to HT stress, while this reduction could be partially recovered by exogenous Spd. Spd also slowed the generation rate of O2.- and increased protective enzyme, superoxide dismutase (SOD) and catalase (CAT) activities both under normal and high temperatures, which suggested that Spd may participate in the antioxidant system. Furthermore, genes involved in polyamine synthesis were analyzed. The results show that HT before heading significantly increased the expression of arginine decarboxylase OsADC1, Spd synthase OsSPDS1 and OsSPDS3 and had little effect on the expression of the S-adenosylmethionine decarboxylase OsSAMDC2 and ornithine decarboxylase OsODC1. In addition, exogenous Spd considerably reduced the expression of OsSAMDC2, OsSPDS1 and OsSPDS3 under HT but not the expression of OsADC1. The above mentioned results indicate that the exogenous Spd could help young rice spikelets to resist HT stress by reducing the expression of OsSAMDC2, OsSPDS1 and OsSPDS3, resulting in higher levels of endogenous Spd and Spm, which were also positively correlated with yield. In conclusion, the adverse effect of HT stress on young spikelets seems to be alleviated by increasing the amounts of Spd and Spm, which provides guidance for adaptation to heat stress during rice production.

A study of the knowledge, attitudes and practices of Tibetan yak herders with respect to brucellosis.

Background: Little information is available regarding the knowledge, attitudes and practices (KAP) of the owners of yaks in Tibet with respect to brucellosis. Methods: This manuscript reports on the results of a cross-sectional survey using a structured questionnaire investigating the KAP of 317 yak herders from 34 villages in the three main yak-rearing counties of Maizhokunggar, Damxung and Yadong from April to August 2015. Results: Although 60.6% of the respondents had heard of brucellosis, there was an overall low level of knowledge about the disease. Herders did, however, adopt management/husbandry practices which would reduce transmission of the disease to humans and other animals. Multivariable logistic modelling showed that a better knowledge was predicted by age, production system adopted, education level and number of people in a household. Differences in attitudes and practices were predicted by education level, production system and household size. Conclusions: In order to increase the awareness of herders on brucellosis and to reduce the risk of infection in both humans and other animals, public health education campaigns should be developed and offered to livestock owners in Tibet.

Strong authentication scheme for telecare medicine information systems.

The telecare medicine information system enables or supports health-care delivery services. A secure authentication scheme will thus be needed to safeguard data integrity, confidentiality, and availability. In this paper, we propose a generic construction of smart-card-based password authentication protocol and prove its security. The proposed framework is superior to previous schemes in three following aspects : (1) our scheme is a true two-factor authentication scheme. (2) our scheme can yield a forward secure two-factor authentication scheme with user anonymity when appropriately instantiated. (3) our scheme utilizes each user's unique identity to accomplish the user authentication and does not need to store or verify others's certificates. And yet, our scheme is still reasonably efficient and can yield such a concrete scheme that is even more efficient than previous schemes. Therefore the end result is more practical for the telecare medicine system.

[Microbial characteristics of straw-amended degraded soils in central Tibet and its effect on soil fertility].

This paper studied the dynamics of microbial communities in degraded soils of central Tibet under straw amendment and its effect on soil fertility. The results showed that straw amendment, and soil covering with spring highland barley (Hordeum vulgare var. nudum) straw in particular, could supply a beneficial soil environment for the relatively balanced growth of soil microbes, e.g., reduced water evaporation, appropriate temperature, and increased content of organic matter and nutrients. All the results demonstrated the possibility of straw amendment in recovering soil fertility and in reconstructing of soil structure in a relatively short period.