Interplay between Ca2+/Calmodulin-Mediated Signaling and AtSR1/CAMTA3 during Increased Temperature Resulting in Compromised Immune Response in Plants

Abstract

Changing temperatures are known to affect plant–microbe interactions; however, the molecular mechanism involved in plant disease resistance is not well understood. Here, we report the effects of a moderate change in temperature on plant immune response through Ca2+/calmodulin-mediated signaling. At 30 °C, Pst DC3000 triggered significantly weak and relatively slow Ca2+ influx in plant cells, as compared to that at 18 °C. Increased temperature contributed to an enhanced disease susceptibility in plants; the enhanced disease susceptibility is the result of the compromised stomatal closure induced by pathogens at high temperature. A Ca2+ receptor, AtSR1, contributes to the decreased plant immunity at high temperatures and the calmodulin-binding domain (CaMBD) is required for its function. Furthermore, both salicylic acid biosynthesis (ICS) and salicylic acid receptor (NPR1) are involved in this process. In addition to stomatal control, AtSR1 is involved in high temperature-compromised apoplastic immune response through the salicylic acid signaling pathway. The qRT-PCR data revealed that AtSR1 contributed to increased temperatures-mediated susceptible immune response by regulating SA-related genes in atsr1, such as PR1, ICS1, NPR1, as well as EDS1. Our results indicate that Ca2+ signaling has broad effects on the molecular interplay between changing temperatures as well as plant defense during plant–pathogen interactions.

Duplicated Copy Number Variant of the Maize 9-Lipoxygenase ZmLOX5 Improves 9,10-KODA-Mediated Resistance to Fall Armyworms

“…Another unanticipated finding in this study is that the duplication of ZmLOX5 may contribute to plant drought tolerance, presumably due to increased ABA and 12-OPDA production. ABA is well documented to enhance drought tolerance in plants through the regulation of stomatal closure to reduce water loss by reducing transpiration rate [42,46,47], and increasing evidence also revealed that 12-OPDA is involved in stomatal movement [43,48,49]. The potential involvement of 9,10-KODA in drought tolerance is consistent with another study that showed treatment with this molecule enhanced drought tolerance in wheat [50].…”

Climate change impedes plant immunity mechanisms

“…Recently, Yuan and Poovaiah showed that the Ca 2+ influx induced by Pst DC3000 is blocked in Arabidopsis at high temperature (30°C) compared to ambient temperature (18°C). In addition, the susceptibility to Pst DC3000 was reduced in the atsr1 mutant plant compared to the wild type at both 18°C and 30°C ( Yuan and Poovaiah, 2022 ). Moreover, the authors suggested that AtSR1 increases plant vulnerability to temperature by acting on stomatal and apoplastic immunity in an SA-dependent manner.…”

OsCAMTA3 Negatively Regulates Disease Resistance to Magnaporthe oryzae by Associating with OsCAMTAPL in Rice

“…AtCAMTA3 negatively regulates not only the SA pathway but also the biosynthesis of pipecolic acid (Pip) and N-hydroxypipecolic acid (NHP) by modulating the expression of AGD2-LIKE DEFENSE RESPONSE PROTEIN 1 (ALD1) [38] and AtCBP60g/AtSARD1, respectively [27,32,37]. Furthermore, cold temperature inhibits the ability of AtCAMTA3 to induce gene expression, and high temperature increases the temperature-mediated susceptible immune response by regulating SA-related genes, such as AtPR1, AtICS1, AtNPR1, and AtEDS1 in atcamta3 [26,43]. The atcamta3 phenotypes can also be rescued by the mutation of two NLR genes, AtDSC1 and AtDSC2.…”