Divergence in function and expression of the NOD26-like intrinsic proteins in plants

<p>Abstract</p> <p>Background</p> <p>NOD26-like intrinsic proteins (NIPs) that belong to the aquaporin superfamily are plant-specific and exhibit a similar three-dimensional structure. Experimental evidences however revealed that functional divergence should have extensively occurred among NIP genes. It is therefore intriguing to further investigate the evolutionary mechanisms being responsible for the functional diversification of the NIP genes. To better understand this process, a comprehensive analysis including the phylogenetic, positive selection, functional divergence, and transcriptional analysis was carried out.</p> <p>Results</p> <p>The origination of NIPs could be dated back to the primitive land plants, and their diversification would be no younger than the emergence time of the moss <it>P. patens</it>. The rapid proliferation of NIPs in plants may be primarily attributed to the segmental chromosome duplication produced by polyploidy and tandem duplications. The maximum likelihood analysis revealed that <it>NIPs </it>should have experienced strong selective pressure for adaptive evolution after gene duplication and/or speciation, prompting the formation of distinct <it>NIP </it>groups. Functional divergence analysis at the amino acid level has provided strong statistical evidence for shifted evolutionary rate and/or radical change of the physiochemical properties of amino acids after gene duplication, and DIVERGE2 has identified the critical amino acid sites that are thought to be responsible for the divergence for further investigation. The expression of plant NIPs displays a distinct tissue-, cell-type-, and developmental specific pattern, and their responses to various stress treatments are quite different also. The differences in organization of <it>cis</it>-acting regulatory elements in the promoter regions may partially explain their distinction in expression.</p> <p>Conclusion</p> <p>A number of analyses both at the DNA and amino acid sequence levels have provided strong evidences that plant NIPs have suffered a high divergence in function and expression during evolution, which is primarily attributed to the strong positive selection or a rapid change of evolutionary rate and/or physiochemical properties of some critical amino acid sites.</p

Advance in sex differentiation in cucumber

Cucumber belongs to the family Cucurbitaceae (melon genus) and is an annual herbaceous vegetable crop. Cucumber is an important cash crop that is grown all over the world. From morphology to cytology, from canonical genetics to molecular biology, researchers have performed much research on sex differentiation and its regulatory mechanism in cucumber, mainly in terms of cucumber sex determination genes, environmental conditions, and the effects of plant hormones, revealing its genetic basis to improve the number of female flowers in cucumber, thus greatly improving the yield of cucumber. This paper reviews the research progress of sex differentiation in cucumber in recent years, mainly focusing on sex-determining genes, environmental conditions, and the influence of phytohormones in cucumber, and provides a theoretical basis and technical support for the realization of high and stable yield cultivation and molecular breeding of cucumber crop traits

Transcriptome Analysis of the Development of Pedicel Abscission Zone in Tomato

Plant organ abscission is a common phenomenon that occurs at a specific position called the abscission zone (AZ). The differentiation and development of the pedicel AZ play important roles in flower and fruit abscission, which are of great significance for abscission in tomatoes before harvest. Previous studies have reported some genes involved in AZ differentiation; however, the genes regulating pedicel AZ cell development in tomatoes after AZ differentiation remain poorly understood. In this study, transcriptome analyses of tomato pedicel AZ samples were performed at 0, 5, 15, and 30 days post-anthesis (DPA). Pedicel AZ growth was mainly observed before 15 DPA. A principal component analysis and a correlation analysis were carried out in order to compare the repeatability and reliability for different samples. We observed 38 up-regulated and 31 down-regulated genes that were significantly altered during 0 to 5 DPA, 5 to 15 DPA, and 0 to 15 DPA, which may play key roles in AZ cell enlargement. GO and KEGG enrichment analyses of the selected DEGs under all three different comparisons were conducted. Auxin-signaling-related genes were analyzed, as well as AUX/IAA, GH3, and small auxin up-regulated RNA (SAUR) gene expression patterns. The presented results provide information on pedicel AZ development, which might help in regulating flower or fruit pedicel abscission in tomato production facilities

Advances in Understanding Silicon Transporters and the Benefits to Silicon-Associated Disease Resistance in Plants

Silicon (Si) is the second most abundant element after oxygen in the earth’s crust and soil. It is available for plant growth and development, and it is considered as quasi-essential for plant growth. The uptake and transport of Si is mediated by Si transporters. With the study of the molecular mechanism of Si uptake and transport in higher plants, different proteins and coding genes with different characteristics have been identified in numerous plants. Therefore, the accumulation, uptake and transport mechanisms of Si in various plants appear to be quite different. Many studies have reported that Si is beneficial for plant survival when challenged by disease, and it can also enhance plant resistance to pathogens, even at low Si accumulation levels. In this review, we discuss the distribution of Si in plants, as well as Si uptake, transport and accumulation, with a focus on recent advances in the study of Si transporters in different plants and the beneficial roles of Si in disease resistance. Finally, the application prospects are reviewed, leading to an exploration of the benefits of Si uptake for plant resistance against pathogens

Advances in Understanding Silicon Transporters and the Benefits to Silicon-Associated Disease Resistance in Plants

Silicon (Si) is the second most abundant element after oxygen in the earth&rsquo;s crust and soil. It is available for plant growth and development, and it is considered as quasi-essential for plant growth. The uptake and transport of Si is mediated by Si transporters. With the study of the molecular mechanism of Si uptake and transport in higher plants, different proteins and coding genes with different characteristics have been identified in numerous plants. Therefore, the accumulation, uptake and transport mechanisms of Si in various plants appear to be quite different. Many studies have reported that Si is beneficial for plant survival when challenged by disease, and it can also enhance plant resistance to pathogens, even at low Si accumulation levels. In this review, we discuss the distribution of Si in plants, as well as Si uptake, transport and accumulation, with a focus on recent advances in the study of Si transporters in different plants and the beneficial roles of Si in disease resistance. Finally, the application prospects are reviewed, leading to an exploration of the benefits of Si uptake for plant resistance against pathogens

Isolation and Expression of Glucosinolate Synthesis Genes &lt;em&gt;CYP83A1&lt;/em&gt; and &lt;em&gt;CYP83B1&lt;/em&gt; in Pak Choi (&lt;em&gt;Brassica &lt;/em&gt;&lt;em&gt;rapa&lt;/em&gt; L. ssp. &lt;em&gt;c&lt;/em&gt;&lt;em&gt;hinensis&lt;/em&gt; var. &lt;em&gt;c&lt;/em&gt;&lt;em&gt;ommunis&lt;/em&gt; (N. Tsen &amp; S.H. Lee) Hanelt)

&lt;em&gt;CYP83A1&lt;/em&gt; and &lt;em&gt;CYP83B1&lt;/em&gt; are two key synthesis genes in the glucosinolate biosynthesis pathway. &lt;em&gt;CYP83A1&lt;/em&gt; mainly metabolizes the aliphatic oximes to form aliphatic glucosinolate and &lt;em&gt;CYP83B1&lt;/em&gt; mostly catalyzes aromatic oximes to synthesis corresponding substrates for aromatic and indolic glucosinolates. In this study, two &lt;em&gt;CYP83A1&lt;/em&gt; genes named &lt;em&gt;BcCYP83A1-1&lt;/em&gt; (JQ289997), &lt;em&gt;BcCYP83A1-2&lt;/em&gt; (JQ289996) respectively and one &lt;em&gt;CYP83B1&lt;/em&gt; (&lt;em&gt;BcCYP83B1&lt;/em&gt;, HM347235) gene were cloned from the leaves of pak choi (&lt;em&gt;Brassica rapa&lt;/em&gt; L. ssp. &lt;em&gt;chinensis &lt;/em&gt;var. &lt;em&gt;communis &lt;/em&gt;(N. Tsen &amp; S.H. Lee) Hanelt) “Hangzhou You Dong Er” cultivar. Their ORFs were 1506, 1509 and 1500 bp in length, encoding 501, 502 and 499 amino acids, respectively. The predicted amino acid sequences of &lt;em&gt;CYP83A1-1&lt;/em&gt;, &lt;em&gt;CYP83A1-2 &lt;/em&gt;and &lt;em&gt;CYP83B1&lt;/em&gt; shared high sequence identity of 87.65, 86.48 and 95.59% to the corresponding ones in &lt;em&gt;Arabidopsis&lt;/em&gt;, and 98.80, 98.61 and 98.80% to the corresponding ones in &lt;em&gt;Brassica pekinensis &lt;/em&gt;(Chinese cabbage), respectively. Quantitative real-time PCR analysis indicated that both &lt;em&gt;CYP83A1&lt;/em&gt; and &lt;em&gt;CYP83B1&lt;/em&gt; expressed in roots, leaves and petioles of pak choi, while the transcript abundances of &lt;em&gt;CYP83A1 &lt;/em&gt;were higher in leaves than in petioles and roots, whereas &lt;em&gt;CYP83B1 &lt;/em&gt;showed higher abundances in roots. The expression levels of glucosinolate biosynthetic genes were consistent with the glucosinolate profile accumulation in shoots of seven cultivars and three organs. The isolation and characterization of the glucosinolate synthesis genes in pak choi would promote the way for further development of agronomic traits via genetic engineering

Variation of Fine Roots Distribution in Apple (<i>Malus pumila</i> M.)–Crop Intercropping Systems on the Loess Plateau of China

In arid and semi-arid areas, interspecific below-ground competition is prominent in agroforestry systems. To provide theoretical and technical guidance for the scientific management of apple&#8315;crop intercropping systems, a field study was conducted in the Loess Plateau of China to examine the variation of fine roots distribution in apple&#8315;crop intercropping systems. The fine roots of apple trees and crops (soybean (Glycine max (L.) Merr) or peanuts (Arachis hypogaea Linn.)) were sampled to 100 cm depth at ten distances from the tree row using the stratified excavation method. The results showed that the vertical distribution of fine roots between intercropped apple trees and intercropped crops were skewed and overlapped. Apple&#8315;crop intercropping inhibited the fine roots of apple trees in the 0&#8315;60 cm soil depth, but promoted their growth in the 60&#8315;100 cm soil depth. However, apple&#8315;crop intercropping inhibited the fine roots of intercropped crops in the 0&#8315;100 cm soil depth. For the fine roots of each component of the apple&#8315;crop intercropping systems, variation in the vertical distribution was much greater than variation in the horizontal distribution. Compared with monocropped systems, apple&#8315;crop intercropping caused the fine roots of intercropped apple trees to move to deeper soil, and those of intercropped crops to move to shallower soil. Additionally, apple&#8315;crop intercropping slightly inhibited the horizontal extension of the fine-root horizontal barycentre (FRHB) of intercropped apple trees and caused the FRHB of intercropped crops to be slightly biased towards the north of the apple tree row. Variation of the fine roots distribution of each component of the apple&#8315;soybean intercropping system was greater than that of the apple&#8315;peanut intercropping system. Thus, the interspecific below-ground competition of the apple&#8315;peanut intercropping system was weaker than that of the apple&#8315;soybean intercropping system. Intense competition occurred in the apple&#8315;peanut intercropping system and the apple&#8315;soybean intercropping system was in sections whose distance ranged from 0.5&#8315;1.3 and 0.5&#8315;1.7 m from the tree row, respectively. The interspecific below-ground competition was fiercer on the south side of the apple tree row than on the north side

How does physical activity improve adolescent resilience? Serial indirect effects via self-efficacy and basic psychological needs

Background Resilience is vital for improving mental health and well-being during adolescence, which is an important yet vulnerable period. Previous research has indicated that physical activity enhances individual resilience. However, limited studies have examined underlying psychological mechanisms between them. The current study aimed to investigate the effect of physical activity on adolescent resilience via self-efficacy and basic psychological needs. Methods A cross-sectional survey was conducted with 1,732 high school students aged 16 to 20 years old (mean age: 16.51 ± 0.77 years), with nearly equal number of boys (47.63%) and girls (52.37%). They each completed the Physical Exercise Questionnaire, Basic Psychological Needs in Exercise Scale, General Self-Efficacy Scale, and Resilience Scale, respectively. A serial indirect model was constructed to examine how physical activity influences resilience. Results Structural equation model analysis revealed that physical activity significantly and directly predicted resilience. When self-efficacy and basic psychological needs were included in the model, both direct and indirect effects were observed. Specifically, the positive relationship between physical activity and resilience was partially mediated by self-efficacy and basic psychological needs. In addition, basic psychological needs and self-efficacy were found to serially mediate the direct relathonship between physical activity and resilience. Conclusions The present study provides novel theoretical insights into sports psychology by establishing a link between basic psychological needs and self-efficacy. The findings have implications for school administrators and physical education instructors in designing targeted interventions to promote adolescent resilience. These interventions may involve creating supportive environment conductive to fulfilling students’ basic psychological needs, implementing strategies to enhance self-efficacy beliefs, and providing opportunities for skill development and mastery experiences in sports and physical activities

Below-Ground Interspecific Competition of Apple (Malus pumila M.)–Soybean (Glycine max L. Merr.) Intercropping Systems Based on Niche Overlap on the Loess Plateau of China

To provide a scientific basis and technical support for agroforestry management practices, such as interrow configuration and soil water and fertilizer management, a stratified excavation method was performed both to explore the fine-root spatial distribution and niche differentiation and to quantify the below-ground interspecific competition status of 3-, 5-, and 7-year-old apple (Malus pumila M.)&ndash;soybean (Glycine max L. Merr.) intercropping systems and monocropping systems. The fine roots of older trees occupied a larger soil space and had both a greater fine-root biomass density (FRMD) and a greater ability to reduce the FRMD of soybean, but this ability decreased with the distance from the apple tree row. Similarly, the FRMD of apple trees was also adversely affected by soybean plants, but this effect gradually increased with a decrease in tree age or with the distance from the tree row. Compared with that of the 3- and 5-year-old monocropped apple trees, the FRMD of the 3- and 5-year-old intercropped apple trees increased in the 40&ndash;100 cm and 60&ndash;100 cm soil layers, respectively. However, compared with that of the 7-year-old apple and soybean monocropping systems, the FRMD of the 7-year-old intercropped apple trees and soybean plants decreased in each soil layer. Compared with that of the corresponding monocropped systems, the fine-root vertical barycenter (FRVB) of the intercropped apple trees displaced deeper soil and that of the intercropped soybean plants displaced shallower soil. Furthermore, the FRVB of both intercropped apple trees and intercropped soybean plants displaced shallower soil with increasing tree age. Intense below-ground interspecific competition in the 3-, 5-, and 7-year-old apple&ndash;soybean intercropping systems occurred in the 0&ndash;40 cm soil layer at distances of 0.5&ndash;0.9, 0.5&ndash;1.3, and 0.5&ndash;1.7 m from the apple tree row, respectively