A Specialized Histone H1 Variant Is Required for Adaptive Responses to Complex Abiotic Stress and Related DNA Methylation in Arabidopsis.

Linker (H1) histones play critical roles in chromatin compaction in higher eukaryotes. They are also the most variable of the histones, with numerous nonallelic variants cooccurring in the same cell. Plants contain a distinct subclass of minor H1 variants that are induced by drought and abscisic acid and have been implicated in mediating adaptive responses to stress.

The F-box protein MAX2 contributes to resistance to bacterial phytopathogens in Arabidopsis thaliana.

Background: The Arabidopsis thaliana F-box protein MORE AXILLARY GROWTH2 (MAX2) has previously been characterized for its role in plant development. MAX2 appears essential for the perception of the newly characterized phytohormone strigolactone, a negative regulator of polar auxin transport in Arabidopsis.

Results: A reverse genetic screen for F-box protein mutants altered in their stress responses identified MAX2 as a component of plant defense.

To open or to close: species-specific stomatal responses to simultaneously applied opposing environmental factors.

Plant stomatal responses to single environmental factors are well studied; however, responses to a change in two (or more) factors - a common situation in nature - have been less frequently addressed. We studied the stomatal responses to a simultaneous application of opposing environmental factors in six evolutionarily distant mono- and dicotyledonous herbs representing different life strategies (ruderals, competitors and stress-tolerators) to clarify whether the crosstalk between opening- and closure-inducing pathways leading to stomatal response is universal or species-specific. Custom-made gas exchange devices were used to study the stomatal responses to a simultaneous application of two opposing factors: decreased/increased CO2 concentration and light availability or reduced air humidity.