Protocol for analyzing the movement and uptake of isotopically labeled signaling molecule azelaic acid in Arabidopsis.

Understanding the generation, movement, uptake, and perception of mobile defense signals is key for unraveling the systemic resistance programs in flowering plants against pathogens. Here, we present a protocol for analyzing the movement and uptake of isotopically labeled signaling molecule azelaic acid (AZA) in Arabidopsis thaliana. We describe steps to assess C-AZA uptake into leaf discs and its movement from local to systemic tissues.

Antigravitropic PIN polarization maintains non-vertical growth in lateral roots.

Lateral roots are typically maintained at non-vertical angles with respect to gravity. These gravitropic setpoint angles are intriguing because their maintenance requires that roots are able to effect growth response both with and against the gravity vector, a phenomenon previously attributed to gravitropism acting against an antigravitropic offset mechanism. Here we show how the components mediating gravitropism in the vertical primary root-PINs and phosphatases acting upon them-are reconfigured in their regulation such that lateral root growth at a range of angles can be maintained.

The Analysis of Gravitropic Setpoint Angle Control in Plants.

The history of research on gravitropism has been largely confined to the primary root-shoot axis and to understanding how the typically vertical orientation observed there is maintained. Many lateral organs are gravitropic too and are often held at specific non-vertical angles relative to gravity. These so-called gravitropic setpoint angles (GSAs) are intriguing because their maintenance requires that root and shoot lateral organs are able to effect tropic growth both with and against the gravity vector.

Auxin in Root Development.

Root system architecture is an important determinant of below-ground resource capture and hence overall plant fitness. The plant hormone auxin plays a central role in almost every facet of root development from the cellular to the whole-root-system level. Here, using as a model, we review the multiple gene signaling networks regulated by auxin biosynthesis, conjugation, and transport that underpin primary and lateral root development.

Kinases and protein motifs required for AZI1 plastid localization and trafficking during plant defense induction.

The proper subcellular localization of defense factors is an important part of the plant immune system. A key component for systemic resistance, lipid transfer protein (LTP)-like AZI1, is needed for the systemic movement of the priming signal azelaic acid (AZA) and a pool of AZI1 exists at the site of AZA production, the plastid envelope. Moreover, after systemic defense-triggering infections, the proportion of AZI1 localized to plastids increases.

Peg Biology: Deciphering the Molecular Regulations Involved During Peanut Peg Development.

Peanut or groundnut is one of the most important legume crops with high protein and oil content. The high nutritional qualities of peanut and its multiple usage have made it an indispensable component of our daily life, in both confectionary and therapeutic food industries. Given the socio-economic significance of peanut, understanding its developmental biology is important in providing a molecular framework to support breeding activities.

An Improved Bioassay to Study Induced Systemic Resistance (ISR) Against Bacterial Pathogens and Insect Pests.

The plant immune system is essential for plants to perceive and defend against bacterial, fungal and insect pests and pathogens. Induced systemic resistance (ISR) is a systemic immune response that occurs upon root colonization by beneficial microbes. A well-studied model for ISR is the association of specific beneficial strains of spp.

Underground Azelaic Acid-Conferred Resistance to Pseudomonas syringae in Arabidopsis.

Local interactions between individual plant organs and diverse microorganisms can lead to whole plant immunity via the mobilization of defense signals. One such signal is the plastid lipid-derived oxylipin azelaic acid (AZA). Arabidopsis lacking AZI1 or EARLI1, related lipid transfer family proteins, exhibit reduced AZA transport among leaves and cannot mount systemic immunity.

The developmental and environmental regulation of gravitropic setpoint angle in Arabidopsis and bean.

Root and shoot branches are major determinants of plant form and critical for the effective capture of resources below and above ground. These branches are often maintained at specific angles with respect to gravity, known as gravitropic set point angles (GSAs). We have previously shown that the mechanism permitting the maintenance of non-vertical GSAs is highly auxin-dependent and here we investigate the developmental and environmental regulation of root and shoot branch GSA.

Analysis of gravitropic setpoint angle control in Arabidopsis.

The history of research on gravitropism has been largely confined to the primary root-shoot axis and to understanding how the typically vertical orientation observed there is maintained. Many lateral organs are gravitropic too and are often held at specific non-vertical angles relative to gravity. These so-called gravitropic setpoint angles (GSAs) are intriguing because their maintenance requires that root and shoot lateral organs are able to effect tropic growth both with and against the gravity vector.

Shoot and root branch growth angle control-the wonderfulness of lateralness.

The overall shape of plants, the space they occupy above and below ground, is determined principally by the number, length, and angle of their lateral branches. The function of these shoot and root branches is to hold leaves and other organs to the sun, and below ground, to provide anchorage and facilitate the uptake of water and nutrients. While in some respects lateral roots and shoots can be considered mere iterations of the primary root-shoot axis, in others there are fundamental differences in their biology, perhaps most conspicuously in the regulation their angle of growth.

Auxin controls gravitropic setpoint angle in higher plant lateral branches.

Lateral branches in higher plants are often maintained at specific angles with respect to gravity, a quantity known as the gravitropic setpoint angle (GSA) [1]. Despite the importance of GSA control as a fundamental determinant of plant form, the mechanisms underlying gravity-dependent angled growth are not known. Here we address the central questions of how stable isotropic growth of a branch at a nonvertical angle is maintained and of how the value of that angle is set.