Integrative Approach for Precise Genotyping and Transcriptomics of Salt Tolerant Introgression Rice Lines.

Rice is the most salt sensitive cereal crop and its cultivation is particularly threatened by salt stress, which is currently worsened due to climate change. This study reports the development of salt tolerant introgression lines (ILs) derived from crosses between the salt tolerant rice variety FL478, which harbors the quantitative trait (QTL), and the salt-sensitive elite cultivar OLESA. Genotyping-by-sequencing (GBS) and Kompetitive allele specific PCR (KASPar) genotyping, in combination with step-wise phenotypic selection in hydroponic culture, were used for the identification of salt-tolerant ILs.

A novel Transposable element-derived microRNA participates in plant immunity to rice blast disease.

MicroRNAs (miRNAs) are small non-coding RNAs that direct post-transcriptional gene silencing in plant development and stress responses through cleavage or translational repression of target mRNAs. Here, we report the identification and functional characterization of a new member of the miR812 family in rice (named as miR812w) involved in disease resistance. miR812w is present in cultivated Oryza species, both japonica and indica subspecies, and wild rice species within the Oryza genus, but not in dicotyledonous species.

Control of flowering in rice through synthetic microProteins.

Photoperiod-dependent flowering in rice is regulated by HEADING DATE 1 (Hd1), which acts as both an activator and repressor of flowering in a daylength-dependent manner. To investigate the use of microProteins as a tool to modify rice sensitivity to the photoperiod, we designed a synthetic Hd1 microProtein (Hd1miP) capable of interacting with Hd1 protein, and overexpressed it in rice. Transgenic OX-Hd1miP plants flowered significantly earlier than wild type plants when grown in non-inductive long day conditions.

A transcription factor coordinating internode elongation and photoperiodic signals in rice.

In several plant species, inflorescence formation is accompanied by stem elongation. Both processes are accelerated in rice upon perception of shortening days. Here, we show that PREMATURE INTERNODE ELONGATION 1 (PINE1), encoding a rice zinc-finger transcription factor, reduces the sensitivity of the stem to gibberellin (GA).

The Importance of Being on Time: Regulatory Networks Controlling Photoperiodic Flowering in Cereals.

Flowering is the result of the coordination between genetic information and environmental cues. Gene regulatory networks have evolved in plants in order to measure diurnal and seasonal variation of day length (or photoperiod), thus aligning the reproductive phase with the most favorable season of the year. The capacity of plants to discriminate distinct photoperiods classifies them into long and short day species, depending on the conditions that induce flowering.

Transcriptional and Post-transcriptional Mechanisms Limit Heading Date 1 (Hd1) Function to Adapt Rice to High Latitudes.

Rice flowering is controlled by changes in the photoperiod that promote the transition to the reproductive phase as days become shorter. Natural genetic variation for flowering time has been largely documented and has been instrumental to define the genetics of the photoperiodic pathway, as well as providing valuable material for artificial selection of varieties better adapted to local environments. We mined genetic variation in a collection of rice varieties highly adapted to European regions and isolated distinct variants of the long day repressor HEADING DATE 1 (Hd1) that perturb its expression or protein function.

Loss of floral repressor function adapts rice to higher latitudes in Europe.

The capacity to discriminate variations in day length allows plants to align flowering with the most favourable season of the year. This capacity has been altered by artificial selection when cultivated varieties became adapted to environments different from those of initial domestication. Rice flowering is promoted by short days when HEADING DATE 1 (Hd1) and EARLY HEADING DATE 1 (Ehd1) induce the expression of florigenic proteins encoded by HEADING DATE 3a (Hd3a) and RICE FLOWERING LOCUS T 1 (RFT1).

Molecular control of seasonal flowering in rice, arabidopsis and temperate cereals.

Background: Rice (Oryza sativa) and Arabidopsis thaliana have been widely used as model systems to understand how plants control flowering time in response to photoperiod and cold exposure. Extensive research has resulted in the isolation of several regulatory genes involved in flowering and for them to be organized into a molecular network responsive to environmental cues. When plants are exposed to favourable conditions, the network activates expression of florigenic proteins that are transported to the shoot apical meristem where they drive developmental reprogramming of a population of meristematic cells.

A rice calcium-dependent protein kinase is expressed in cortical root cells during the presymbiotic phase of the arbuscular mycorrhizal symbiosis.

Background: The arbuscular mycorrhizal (AM) symbiosis consists of a mutualistic relationship between soil fungi and roots of most plant species. This association provides the arbuscular mycorrhizal fungus with sugars while the fungus improves the uptake of water and mineral nutrients in the host plant. Then, the establishment of the arbuscular mycorrhizal (AM) symbiosis requires the fine tuning of host gene expression for recognition and accommodation of the fungal symbiont.

Laser microdissection reveals that transcripts for five plant and one fungal phosphate transporter genes are contemporaneously present in arbusculated cells.

The establishment of a symbiotic interaction between plant roots and arbuscular mycorrhizal (AM) fungi requires both partners to undergo significant morphological and physiological modifications which eventually lead to reciprocal beneficial effects. Extensive changes in gene expression profiles recently have been described in transcriptomic studies that have analyzed the whole mycorrhizal root. However, because root colonization by AM fungi involves different cell types, a cell-specific gene expression pattern is likely to occur.

Sucrose-mediated priming of plant defense responses and broad-spectrum disease resistance by overexpression of the maize pathogenesis-related PRms protein in rice plants.

Expression of pathogenesis-related (PR) genes is part of the plant's natural defense response against pathogen attack. The PRms gene encodes a fungal-inducible PR protein from maize. Here, we demonstrate that expression of PRms in transgenic rice confers broad-spectrum protection against pathogens, including fungal (Magnaporthe oryzae, Fusarium verticillioides, and Helminthosporium oryzae) and bacterial (Erwinia chrysanthemi) pathogens.