OsMKK3, a Stress-Responsive Protein Kinase, Positively Regulates Rice Resistance to Nilaparvata lugens via Phytohormone Dynamics

Abstract

Plants undergo several but very precise molecular, physiological, and biochemical modulations in response to biotic stresses. Mitogen-activated protein kinase (MAPK) cascades orchestrate multiple cellular processes including plant growth and development as well as plant responses against abiotic and biotic stresses. However, the role of MAPK kinases (MAPKKs/MKKs/MEKs) in the regulation of plant resistance to herbivores has not been extensively investigated. Here, we cloned a rice MKK gene, OsMKK3, and investigated its function. It was observed that mechanical wounding, infestation of brown planthopper (BPH) Nilaparvata lugens, and treatment with methyl jasmonate (MeJA) or salicylic acid (SA) could induce the expression of OsMKK3. The over-expression of OsMKK3 (oe-MKK3) increased levels of jasmonic acid (JA), jasmonoyl-L-isoleucine (JA-Ile), and abscisic acid (ABA), and decreased SA levels in rice after BPH attack. Additionally, the preference for feeding and oviposition, the hatching rate of BPH eggs, and BPH nymph survival rate were significantly compromised due to over-expression of OsMKK3. Besides, oe-MKK3 also augmented chlorophyll content but impaired plant growth. We confirm that MKK3 plays a pivotal role in the signaling pathway. It is proposed that OsMKK3 mediated positive regulation of rice resistance to BPH by means of herbivory-induced phytohormone dynamics.

Suppression of a leucine‐rich repeat receptor‐like kinase enhances host plant resistance to a specialist herbivore

“…BPH is a phloem feeder which causes substantial yield losses and is among the most damaging rice pests on earth (Heong, Cheng, & Escalada, 2016). Although rice plants can activate a variety of defense signaling molecules, including MPKs, WRKYs, JA, SA, ET and H 2 O 2 , and then produce defense responses when infested by BPH (Hu et al, 2016;Li, Liu, et al, 2019;Lu et al, 2014;Ma et al, 2020;Zhou et al, 2009Zhou et al, , 2019, BPH can also circumvent and suppress host plant resistance in several ways (Ji et al, 2017;Ye et al, 2017). BPH can, for instance, secrete salivary endo-β-1,4-glucanase to overcome plant cell wall defense in rice without inducing defense-related signal molecules (Ji et al, 2017), and can inhibit H 2 O 2 production in rice via reducing cellular Ca 2+ levels by secreting salivary calcium-binding proteins (Ye et al, 2017).…”

Two splice variants of the DsMEK1 mitogen-activated protein kinase kinase (MAPKK) is involved different way in salt stress regulation in Dunaliella salina

“…DsMEK1-X1 and DsMEK1-X2 were categorized into subfamily B, which contains AtMKK3 and OsMKK3 suggesting that DsMEK1-X1 and DsMEK1-X2 possessed the close evolutionary relationship with AtMKK3 and OsMKK3. Previous studies revealed that AtMKK3 was induced by ABA or salt stress treatments [30], and treatment with methyl jasmonate (MeJA) or salicylic acid (SA) could induced the expression of OsMKK3 [31]. Thus, the phylogenetic tree analysis suggested that DsMEK1-X1 and DsMEK1-X2 may involve in abiotic stress.…”

Two splice variants of the DsMEK1 mitogen-activated protein kinase kinase (MAPKK) are involved in salt stress regulation in Dunaliella salina in different ways

“…DsMEK1-X1 and DsMEK1-X2 were categorized into subfamily B, which contains AtMKK3 and OsMKK3, suggesting that DsMEK1-X1 and DsMEK1-X2 possessed a close evolutionary relationship with AtMKK3 and OsMKK3. Previous studies revealed that AtMKK3 was induced by ABA or salt stress treatments [25], and treatment with methyl jasmonate (MeJA) or salicylic acid (SA) could induce the expression of OsMKK3 [26]. Thus, the phylogenetic tree analysis suggested that DsMEK1-X1 and DsMEK1-X2 may be involved in abiotic stress.…”