OsTIR1 and OsAFB2 Downregulation via OsmiR393 Overexpression Leads to More Tillers, Early Flowering and Less Tolerance to Salt and Drought in Rice

The microRNA miR393 has been shown to play a role in plant development and in the stress response by targeting mRNAs that code for the auxin receptors in Arabidopsis. In this study, we verified that two rice auxin receptor gene homologs (OsTIR1 and OsAFB2) could be targeted by OsmiR393 (Os for Oryza sativa). Two new phenotypes (increased tillers and early flowering) and two previously observed phenotypes (reduced tolerance to salt and drought and hyposensitivity to auxin) were observed in the OsmiR393-overexpressing rice plants. The OsmiR393-overexpressing rice demonstrated hyposensitivity to synthetic auxin-analog treatments. These data indicated that the phenotypes of OsmiR393-overexpressing rice may be caused through hyposensitivity to the auxin signal by reduced expression of two auxin receptor genes (OsTIR1 and OsAFB2). The expression of an auxin transporter (OsAUX1) and a tillering inhibitor (OsTB1) were downregulated by overexpression of OsmiR393, which suggested that a gene chain from OsmiR393 to rice tillering may be from OsTIR1 and OsAFB2 to OsAUX1, which affected the transportation of auxin, then to OsTB1, which finally controlled tillering. The positive phenotypes (increased tillers and early flowering) and negative phenotypes (reduced tolerance to salt and hyposensitivity to auxin) of OsmiR393-overexpressing rice present a dilemma for molecular breeding

The scheme of wind-storage combined system capacity configuration based on random fuzzy chance constrained bi-level programming

A random fuzzy chance constrained bilevel programming scheme for distributed wind-storage combined system is proposed. The random fuzzy simulation is used to describe the uncertainty of distributed wind power output. The reliability of randomness and ambiguity is taken as the index to evaluate the capacity allocation scheme of the distributed wind-storage combined system. Considering system power balance, opportunity measurement constraint of static security index and active management (AM) measures, the random fuzzy expectation value of maximum annual profit is set as the upper optimization goal, and the minimum random fuzzy expectation value of the distributed wind power active reduction is set as the lower optimization target. The scheme is constructed by judging whether the static security index of the upper goal satisfies the confidence level of the random fuzzy chance constraint and the coordination of the upper and lower goals. Finally, the random fuzzy simulation, the forward pushback power flow calculation and the genetic algorithm (GA) are applied to solve the model. The simulation result of IEEE 14-bus example shows the effectiveness and superiority of the model and scheme

The scheme of wind-storage combined system capacity configuration based on random fuzzy chance constrained bi-level programming

A random fuzzy chance constrained bilevel programming scheme for distributed wind-storage combined system is proposed. The random fuzzy simulation is used to describe the uncertainty of distributed wind power output. The reliability of randomness and ambiguity is taken as the index to evaluate the capacity allocation scheme of the distributed wind-storage combined system. Considering system power balance, opportunity measurement constraint of static security index and active management (AM) measures, the random fuzzy expectation value of maximum annual profit is set as the upper optimization goal, and the minimum random fuzzy expectation value of the distributed wind power active reduction is set as the lower optimization target. The scheme is constructed by judging whether the static security index of the upper goal satisfies the confidence level of the random fuzzy chance constraint and the coordination of the upper and lower goals. Finally, the random fuzzy simulation, the forward pushback power flow calculation and the genetic algorithm (GA) are applied to solve the model. The simulation result of IEEE 14-bus example shows the effectiveness and superiority of the model and scheme

Auxin (IAA) contents in <i>OsmiR393</i>-overexpressing rice plants.

<p>The rice was grown in the field during the rice-growing season, and IAA concentrations in flag leaves were measured.</p

Organ-specific expression analysis for the predicted target genes of <i>OsmiR393</i> by semi-quantitative RT-PCR.

<p>Total RNA was isolated from booting rice plants grown in the natural field. Rice <i>Actin1</i> was used as an internal control. <i>OsAFB2-1</i> and <i>OsAFB2-2</i> are two alternatively spliced mRNAs of <i>OsAFB2</i>. The term “cycles” indicates the PCR cycle number used in RT-PCR reactions.</p

Putative target genes for <i>OsmiR393</i> in rice predicted based on the sequence complementarity.

<p>The putative target genes for <i>OsmiR393</i> were predicted using the web-based program (<a href="http://bioinfo3.noble.org/miRNA/miRU.htm" target="_blank">http://bioinfo3.noble.org/miRNA/miRU.htm</a>).</p>a<p>Mismatch nucleotides in target mRNAs with <i>OsmiR393</i> are underlined.</p

Expression comparison of genes downstream of <i>OsAFB2</i> and <i>OsTIR1</i> that control the tillers and flowering time.

<p>Total RNA was isolated from the booting rice plants grown in field. Rice <i>Actin1</i> was used as an internal control. Two auxin transporter homologs (<b>A, B</b>), an enhancing tiller gene (<b>C</b>), a tillering inhibitor (<b>D</b>) and two genes promoting flowering (<b>E, F</b>) of rice were compared.</p

Expression identification of the predicted target mRNAs in <i>OsmiR393</i>-overexpressing transgenic lines.

<p>Transcript levels of the target mRNAs were measured by real-time RT-PCR when the rice plants were grown in the natural field. The plots represent the relative expression (fold) of each gene in the transgenic plants compared with the expression of <i>Actin1</i>. Mean values and standard errors were obtained from three independent experiments.</p

Effects of 1-naphthaleneacetic acid (NAA, a synthetic auxin analog) on root growth.

<p>Seeds were germinated in different concentrations of NAA for 10 days in the dark at 26±2°C. Bar = 1.0 cm; * and ** indicate significance by the Duncan's multiple range tests at the 5% or 1% level, respectively.</p

Response to drought and salt treatments.

<p><b>A.</b> Growth was affected by drought stress. The 6-day seedlings of <i>OsmiR393</i>-overexpressing rice and controls were removed from Hoagland's Solution for one day and then re-cultured in Hoagland's Solution for 4 days. <b>B.</b> Images were taken on the fifth day after 10-day seedlings were placed in 100 mM NaCl. <b>C.</b> The germination ratio was calculated after the seeds germinated in 150 and 200 mM NaCl for 15 days; ** indicates significance by the Duncan's multiple range tests at the 1% level.</p