This article has been cited by other articles in PMC. Although in animals there is direct evidence implicating particular miRNAs in the control of developmental timing, to date it is not known whether plant miRNAs also play a role in regulating temporal transitions. Through an activation-tagging approach, we demonstrate that miRNA miR causes early flowering and disrupts the specification of floral organ identity when overexpressed in Arabidopsis.
Advanced Search Abstract In Larix and in some crops, heterosis is prevalent and has been widely used in breeding to produce excellent varieties. However, the molecular basis of heterosis in Larix remains ambiguous.
Here, the function and regulation of LaAP2L1 were further explored. Fresh weight of leaves was almost twice as great as in vector controls. Likewise, seed yield of 35S:: The enlarged organs and heterosis-like traits displayed by 35S:: LaAP2L1 plants were mainly due to enhanced cell proliferation and prolonged growth duration.
These findings provide new insights into the formation of heterosis in woody plants and suggest that LaAP2L1 has potential applications in breeding high-yielding crops and energy plants. This provided information that will be important in further revealing the functions of these transcription factors.
Introduction Heterosis or hybrid vigor, prevalent in higher plants, refers to the phenomenon whereby hybrid progeny display improved grain yield, growth potential, resistance to pests, and environmental stresses compared with their parents GuoSchnable and Springer As a direct consequence of hybridization events, heterosis has been demonstrated to play a critical role in promoting speciation and evolution of various plants.
Moreover, this phenomenon has been widely used in breeding crops and other economic plants. F1 hybrids can produce yields two to three times as high as their inbred parents in rice, maize, wheat, and other crops DuvickSpringer et al.
As a result, large-scale cultivation of hybrid varieties, particularly the worldwide promotion and planting of hybrid rice, has made significant contributions to food production and provided great economic and societal benefits DuvickGuo et al.
However, although three main genetic hypotheses—the dominance, overdominance and epistasis hypotheses—have been proposed to explain the origin of heterosis Li ZK et al. Studies focusing on gene transcription have provided further insights into the molecular basis of heterosis, demonstrating that differences in gene expression, especially nonadditive expression, are tightly associated with the formation of heterotic traits in many plant species Swanson-Wagner et al.
Several genes involved in the formation of heterosis have been studied. Ghd7, encoding a CCT domain protein, significantly improved the yield and adaptability of indicia rice Xue et al.
However, to date only a few genes have been shown to function in heterosis and thus our understanding of the mechanism of heterosis remains poor. Heterosis is mainly manifested in two ways.
One is improved biomass, e. The other is higher environmental adaptability, such as resilience Baranwal et al. Therefore, the genes involved in regulating organ development, especially organ size, may potentially contribute to the formation of heterotic traits as shown by improved yield or biomass, although no evidence of direct relationship between organ size-associated genes and heterosis has been reported.
Overexpression of ANT increases leaf size and floral organ growth, whereas loss of ANT function reduces the sizes of leaves and floral organs Elliott et al.
Therefore, heterosis should be understood from the perspective of organ development regulation in order to provide new information about its molecular basis. Larix, one of the most important afforestation and timber species in the world, has important economic and ecological value.
Like some herbaceous plants, such as rice, maize and Brassica campestris, Larix hybrids also exhibit heterosis, and this phenomenon has been widely exploited in Larix breeding. However, owing in part to its long life cycle and complex genetic background, the intrinsic mechanism of heterosis in Larix remains largely unexplored.
In a previous study, we have indicated that differential gene expression, especially nonadditive expression, is also closely associated with heterosis in Larix, and a series of nonadditive expression genes have been detected Li A et al. Subsequently, the function of LaAP2L1 was explored by overexpression in Arabidopsis, and a series of heterosis-like traits, e.
In addition, the cellular and molecular bases of heterosis-like traits in LaAP2L1 overexpression transgenic lines were analyzed. Results LaAP2L1 is associated with heterosis in Larix hybrids In our previous study, the genome-wide transcript profiles of two Larix genotypes and their reciprocal hybrids were investigated using the microarray method to understand heterosis in Larix kaempferi at the molecular level.
Microarray data revealed that the expression patterns of LaAP2L1 in the two Larix parental lines and their reciprocal hybrids were significantly different. The highest expression level of LaAP2L1 was detected in the heterotic hybrids, while the expression level of LaAP2L1 in the nonheterotic hybrids was close to the mid-parent value.
The results indicated that the expression pattern of LaAP2L1 identified experimentally was fully represented by the microarray data Supplementary Fig. Quantitative expression analysis in individual plants of heterotic hybrids, nonheterotic hybrids, and their parents also verified that the highest expression level of LaAP2L1 was detected in the heterotic hybrids Supplementary Fig.
Expression analysis of the three other Larix cross-combinations also indicated that LaAP2L1 exhibited a higher expression level in the hybrids than in their two parental lines Supplementary Fig. According to the sequence annotation information, five contigs originating from the transcript products of LaAP2L1 were discovered, and they consisted of a unigene Fig.
This cDNA encodes a predicted protein containing amino acids.View Homework Help - Unit 3 Discussion - SC from SC at Kaplan University.
Organ transplantation is when doctors remove an organ, from a living donor or a %(5). We would like to show you a description here but the site won’t allow us. Mar 03, · First, AP2 prevents expression of the C class gene AGAMOUS (AG) in whorls 1 and 2, ensuring that C activity and hence reproductive organ identity is restricted to whorls 3 and 4 of the flower.
Secondly, AP2 has a role in sepal and petal development that can be . The Human Organ Systems. Information. Organ systems are groups of organs within the body that can be thought of as working together as a unit to carry out specific tasks or functions within the body.
The human body is most commonly divided into eleven organ systems, the ones listed below. AP2 Unit 3 discussion on Organ Transplantion Essay and definition are as follows: Autografts which is a transplant procedure where one's own tissue is used to grafts for burns and plastic surgery.
Isograft is a procedure where tissue from an identical twin is used for a tissue transplant. Allograft is a procedure where tissue from different. View Essay - AP2 Unit 3 discussion on Organ Transplantion from SC at Kaplan University. In this units readings contained information about the four varieties of grafts.
They are and definition95%(22).