Screening of Sugarcane Proteins Associated with Defense against Leifsonia xyli subsp. xyli, Agent of Ratoon Stunting Disease.

Sugarcane is the most important sugar crop and one of the leading energy-producing crops in the world. Ratoon stunting disease (RSD), caused by the bacterium Leifsonia xyli subsp. xyli, poses a huge threat to ratoon crops, causing a significant yield loss in sugarcane. Breeding resistant varieties is considered the most effective and fundamental approach to control RSD in sugarcane. The exploration of resistance genes forms the foundation for breeding resistant varieties through molecular technology. The pglA gene is a pathogenicity gene in L. xyli subsp. xyli, encoding an endopolygalacturonase. In this study, the pglA gene from L. xyli subsp. xyli and related microorganisms was analyzed. Then, a non-toxic, non-autoactivating pglA bait was successfully expressed in yeast cells. Simultaneously the yeast two-hybrid library was generated using RNA from the L. xyli subsp. xyli-infected sugarcane. Screening the library with the pglA bait uncovered proteins that interacted with pglA, primarily associated with ABA pathways and the plant immune system, suggesting that sugarcane employs these pathways to respond to L. xyli subsp. xyli, triggering pathogenicity or resistance. The expression of genes encoding these proteins was also investigated in L. xyli subsp. xyli-infected sugarcane, suggesting multiple layers of regulatory mechanisms in the interaction between sugarcane and L. xyli subsp. xyli. This work promotes the understanding of plant-pathogen interaction and provides target proteins/genes for molecular breeding to improve sugarcane resistance to L. xyli subsp. xyli.

Differential Gene Expression Analysis of SoCBL Family Calcineurin B-like Proteins: Potential Involvement in Sugarcane Cold Stress.

Sugarcan e is a major crop for sugar and biofuel production and is cultivated in tropical and subtropical areas worldwide. Sugarcane growth is constrained because of winter's low-temperature stress, and cold resistance is an important limitation in sugarcane growth enhancement. Therefore, in this study, we identified a gene involved in the low-temperature stress response of sugarcane. Calcineurin B-like (CBL) protein is a calcium signal receptor involved in the cold stress response. Five sugarcane CBL genes were cloned, sequenced, and named SoCBL1, SoCBL3, SoCBL5, SoCBL6, and SoCBL9. The protein sequences of these genes were analyzed. The calculated molecular weight of these proteins was 24.5, 25.9, 25.2, 25.6, and 26.3 kD, respectively. Subcellular localization analysis revealed that SoCBL1, SoCBL3, SoCBL6, and SoCBL9 were situated in the cytoplasm, while SoCBL5 was present in mitochondria. Secondary structure analysis showed that these five CBL proteins had similar secondary structures. Conserved domain analysis displayed that each sugarcane CBL protein contained three conserved EF domains. According to the self-expanding values of the phylogenetic tree, the CBL gene family was divided into four groups. The CBL1 and CBL9 genes were classified into one group, illustrating that these two genes might possess a similar function. The expression analysis of the SoCBL gene under low temperatures showed that SoCBL3 and SoCBL5 were affected significantly, while SoCBL1 and SoCBL9 were less affected. These results demonstrate that the CBL genes in sugarcane have similar characteristics and present differences in genetic diversity and gene expression response to low temperatures. Therefore, these genes might be novel candidates for fighting cold stress in sugarcane.

Exploration of silicon functions to integrate with biotic stress tolerance and crop improvement.

In the era of climate change, due to increased incidences of a wide range of various environmental stresses, especially biotic and abiotic stresses around the globe, the performance of plants can be affected by these stresses. After oxygen, silicon (Si) is the second most abundant element in the earth's crust. It is not considered as an important element, but can be thought of as a multi-beneficial quasi-essential element for plants. This review on silicon presents an overview of the versatile role of this element in a variety of plants. Plants absorb silicon through roots from the rhizospheric soil in the form of silicic or monosilicic acid. Silicon plays a key metabolic function in living organisms due to its relative abundance in the atmosphere. Plants with higher content of silicon in shoot or root are very few prone to attack by pests, and exhibit increased stress resistance. However, the more remarkable impact of silicon is the decrease in the number of seed intensities/soil-borne and foliar diseases of major plant varieties that are infected by biotrophic, hemi-biotrophic and necrotrophic pathogens. The amelioration in disease symptoms are due to the effect of silicon on a some factors involved in providing host resistance namely, duration of incubation, size, shape and number of lesions. The formation of a mechanical barrier beneath the cuticle and in the cell walls by the polymerization of silicon was first proposed as to how this element decreases plant disease severity. The current understanding of how this element enhances resistance in plants subjected to biotic stress, the exact functions and mechanisms by which it modulates plant biology by potentiating the host defence mechanism needs to be studied using genomics, metabolomics and proteomics. The role of silicon in helping the plants in adaption to biotic stress has been discussed which will help to plan in a systematic way the development of more sustainable agriculture for food security and safety in the future.

Exploration of silicon functions to integrate with biotic stress tolerance and crop improvement

In the era of climate change, due to increased incidences of a wide range of various environmental stresses, especially biotic and abiotic stresses around the globe, the performance of plants can be affected by these stresses. After oxygen, silicon (Si) is the second most abundant element in the earth's crust. It is not considered as an important element, but can be thought of as a multi-beneficial quasi-essential element for plants. This review on silicon presents an overview of the versatile role of this element in a variety of plants. Plants absorb silicon through roots from the rhizospheric soil in the form of silicic or monosilicic acid. Silicon plays a key metabolic function in living organisms due to its relative abundance in the atmosphere. Plants with higher content of silicon in shoot or root are very few prone to attack by pests, and exhibit increased stress resistance. However, the more remarkable impact of silicon is the decrease in the number of seed intensities/soil-borne and foliar diseases of major plant varieties that are infected by biotrophic, hemi-biotrophic and necrotrophic pathogens. The amelioration in disease symptoms are due to the effect of silicon on a some factors involved in providing host resistance namely, duration of incubation, size, shape and number of lesions. The formation of a mechanical barrier beneath the cuticle and in the cell walls by the polymerization of silicon was first proposed as to how this element decreases plant disease severity. The current understanding of how this element enhances resistance in plants subjected to biotic stress, the exact functions and mechanisms by which it modulates plant biology by potentiating the host defence mechanism needs to be studied using genomics, metabolomics and proteomics. The role of silicon in helping the plants in adaption to biotic stress has been discussed which will help to plan in a systematic way the development of more sustainable agriculture for food security and safety in the future.

[Prevalence and risk factors for anxiety among inhabitants in the relief centers after the 5 *12 Sichuan earthquake].

OBJECTIVE: To investigate the prevalence and risk factors for anxiety among inhabitants in the relief centers one month after the 5 * 12 Sichuan earthquake and to formulate intervention strategies. METHODS: A total of 402 tent inhabitants aged > or = 18 years were randomly selected from 13 relief centers of 4 townships in Jiangyou city. Data were collected by Self-rating Anxiety Scale (SAS) and risk factor questionnaires. RESULTS: The prevalence of anxiety among inhabitants in the relief centers was 22.1% (95% CI: 18.2%-26.6% ) (89/402). In single factor analysis, female, aged > or = 40 years, family per-capita monthly income of < 600 Yuan, education level of less than junior high school, inconvenient living conditions, history of chronic diseases, limited living space in tents, shortage of goods, and sex life being interrupted etc might increase anxiety. In multi-factor analysis, female (OR = 2.921), inconvenient living conditions (OR = 2.475), history of chronic diseases (OR = 3.997), and limited living space in tents (OR = 2.982) were the risk factors for anxiety. CONCLUSION: Inhabitants in the relief centers exhibited higher prevalence of anxiety as compared with the general population. Measures to improve the living conditions of the relief centers, including guarantee of water, electricity and material supply, sewage treatment, living space and privacy, and early psychological interventions were recommended for prevention and relief of anxiety.

[Investigation of anxiety among 402 tent inhabitants in Jiangyou city after the 5.12 Sichuan earthquake].

OBJECTIVE: To investigate the prevalence of anxiety among tent inhabitants one month after the 5.12 Sichuan earthquake as to formulating intervention strategies. METHODS: A stratified random sampling method was adopted. Inclusion criteria were: inhabitants, aged above 18 years old, living in tent in 13 relief centers of 4 townships in Jiangyou city; and only one person from each tent/family could be enrolled in this study. A total of 402 subjects were interviewed with Self-rating Anxiety Scale (SAS). SAS scores were compared between different groups and symptomatic differences between anxiety and non-anxiety victims were analyzed by stepwise multiple regression analysis. RESULTS: The prevalence of anxiety among tent inhabitants was 22.1% (89/402). A higher rate of anxiety was observed in senior age group than in younger age group (F = 7.03, P < 0.01). Age with > or = 50 years (42.85 +/- 11.15), 40-49 years (41.57 +/- 10.30), 30-39 years (37.99 +/- 9.66), 18-29 years (36.62 +/- 9.92). Female (43.13 +/- 10.45) had a high rate of anxiety than male (36.80 +/- 9.88) (t = -6.09, P < 0.01). The most common symptoms were anxiety (79.4%, 319/402), fatigue (68.2%, 274/402), phobia (65.7%, 264/402), sleep disorders (65.4%, 263/402), unfortunate feelings (65.2% , 262/402), akathisia (59.7%, 240/402), and fear (58.2%, 234/402). Stepwise multiple regression analysis revealed that insane feelings(t = 5.37, P < 0.01), trembling(t = 5.33, P < 0.01), dyspnea (t = 4.28, P < 0.01), unfortunate feelings (t = 3.87, P < 0.01), headache(t = 3.85, P < 0.01), facial flushing (t = 3.48, P <0.01), fatigue (t = 3.27, P < 0.01), dizziness (t = 2.79, P < 0.01), frequent micturition (t = 2.41, P < 0.05), and akathisia (t = 2.31, P < 0.05) were more frequently experienced in the anxiety victims than non-anxiety victims. CONCLUSION: Tent inhabitants in the post-earthquake relief centers exhibit a higher prevalence of anxiety as compared with the general population. Much attention should be paid to elderly, female, and those who have developed specific symptoms such as insane feelings, trembling, dyspnea, etc. Meanwhile, some intervention measures should be timely taken.