Cell autonomous and non-autonomous functions of plant intracellular immune receptors in stomatal defense and apoplastic defense.

Stomatal closure defense and apoplastic defense are two major immunity mechanisms restricting the entry and propagation of microbe pathogens in plants. Surprisingly, activation of plant intracellular immune receptor NLR genes, while enhancing whole plant disease resistance, was sometimes linked to a defective stomatal defense in autoimmune mutants. Here we report the use of high temperature and genetic chimera to investigate the inter-dependence of stomatal and apoplastic defenses in autoimmunity.

Gas Exchange and Co-regulation of Photochemical and Nonphotochemical Quenching in Bean during Chilling at Ambient and Elevated Carbon Dioxide.

The effects of elevated (700 micromol mol(-1)) and ambient (350 micromol mol(-1)) CO(2) on gas exchange parameters and chlorophyll fluorescence were measured on bean (Phaseolus vulgaris) during 24 h chilling treatments at 6.5 degrees C. Consistent with previous research on this cultivar, photosynthetic decline during chilling was not significantly affected by CO(2) while post-chilling recovery was more rapid at elevated compared to ambient CO(2).

Effects of elevated carbon dioxide on gas exchange and photochemical and nonphotochemical quenching at low temperature in tobacco plants varying in Rubisco activity.

Elevated (700 micromol mol-1) and ambient (350 micromol mol-1) CO2 effects on total ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity, photosynthesis (A), and photoinhibition during 6 d at low temperature were measured on wild type (WT), and rbcS antisense DNA mutants (T3) of tobacco (Nicotiana tabacum L.) with 60% of WT total Rubisco activity. Prior to the low temperature treatment, A and quantum yield of PSII photochemistry in the light adapted state (phiPSII) were significantly lower in T3 compared to WT at each CO2 level.

Chilling responses of maize (Zea mays L.) seedlings: root hydraulic conductance, abscisic acid, and stomatal conductance.

Maize seedling water relations and abscisic acid (ABA) levels were measured over 24 h of root chilling (5.5 degrees C). At 2.