Ethylene and hydrogen peroxide are involved in brassinosteroid-induced salt tolerance in tomato

Abstract

Crosstalk between phytohormone pathways is essential in plant growth, development and stress responses. Brassinosteroids (BRs) and ethylene are both pivotal plant growth regulators, and the interaction between these two phytohormones in the tomato response to salt stress is still unclear. Here, we explored the mechanism by which BRs affect ethylene biosynthesis and signaling in tomato seedlings under salt stress. The activity of 1-aminocyclopropane-1-carboxylate synthase (ACS), an ethylene synthesis enzyme, and the ethylene signaling pathway were activated in plants pretreated with BRs. Scavenging of ethylene production or silencing of ethylene signaling components inhibited BR-induced salt tolerance and blocked BR-induced activities of several antioxidant enzymes. Previous studies have reported that BRs can induce plant tolerance to a variety of environmental stimuli by triggering the generation of H2O2 as a signaling molecule. We also found that H2O2 might be involved in the crosstalk between BRs and ethylene in the tomato response to salt stress. Simultaneously, BR-induced ethylene production was partially blocked by pretreated with a reactive oxygen species scavenger or synthesis inhibitor. These results strongly demonstrated that ethylene and H2O2 play important roles in BR-dependent induction of plant salt stress tolerance. Furthermore, we also investigated the relationship between BR signaling and ethylene signaling pathways in plant processes responding to salt stress.

Transgenic Breeding Approaches for Improving Abiotic Stress Tolerance: Recent Progress and Future Perspectives

“…The previous study demonstrated that gemini virus replicons (gvrs) could be used to transfer cas9/sgRNA to plant cells with enhanced mutations when the replication initiation protein gene (rep) was co-transformed with Cas9/sgRNA structures [71]. In addition, to develop the practicability of CRISPR-cas9 technology, more efforts are required to make targeted genome editing in plants easier and faster [7,71].…”

“…To improve plant survival and production efficiency, different approaches have been established to improve plant resistance [3,5]. The exposure of plants to these environmental stresses leads to leads to reactive oxygen species (ROS) overproduction, which negatively affects the activities of enzymes, the biosynthesis of carbohydrates, DNA, proteins, and other biochemical activities, thus leading to oxidative stress ( Figure 1) [6,7]. ROS also influence the expression of a number of genes involved in many processes, including growth, the cell cycle, programmed cell death (PCD), abiotic stress responses, pathogen response, systemic signaling, and development [8].…”

Growth and Physiological Responses of Adenophora triphylla (Thunb.) A.DC. Plug Seedlings to Day and Night Temperature Regimes

“…Thus research into the expression of antioxidant isozymes would be helpful in revealing the physiological response of antioxidant enzymes and mechanisms of ROS scavenging under different temperature regimes. As a signaling molecule, endogenous H 2 O 2 at a low level (nmol·g −1 ) plays a role in seedling growth and development and in mediating tolerance by inducing antioxidant enzymes [78,79]. However, high concentration of H 2 O 2 has a negative impact and induces an excessive expression of antioxidant isozymes.…”

Como o manejo do nitrogênio da planta-mãe interfere na biologia de sementes de feijão carioca superprecoce?

“…al., 2013; MINGOTTE et al, 2014).Outro fator relevante é que, apesar do nitrogênio ser o nutriente mais requerido para o feijoeiro, à utilização isolada apresenta reduzida eficácia para o aumento dos teores dos demais nutrientes na sementes (KOLLING; OZELAME, 2017).Sabe-se que os fertilizantes nitrogenados são salinos e altamente solúveis em água.Portanto, podem ser prejudiciais às plantas, causando estresse osmótico e/ou salínico(AZEVEDO et al, 2018). Os efeitos da salinização no solo provocam a diminuição da fertilidade físico-química, desestruturação, aumento da densidade aparente e da retenção de água do solo, redução da infiltração de água pelo excesso de íons sódicos; fisiologicamente na planta são afetados a síntese de proteína, metabolismo de lipídieos e fotossíntese, e até mesmo características morfológicas como a taxa de expansão da superfície foliar (DIAS; BLANCO, 2010;AZEVEDO et al, 2018) O estresse salino aciona a síntese de etileno, que impulsiona a liberação de radicais livres e, então, a produção de brassinoesteróides e jasmonatohormônios relacionados ao metabolismo de defesa(ZHU et al, 2016;JIROUTOVA et al, 2018; PERES et al, 2019). Juntamente à liberação de compostos como ascorbato, glutationa, tocoferol, caratenoides e compostos fenólicos e as enzimas superóxido dismutase, catalase, peroxidase do ascorbato e peroxidase de fenóis(BARBOSA et al, 2014;MAIA et al, 2015;ALVES et al, 2016;ZHU et al, 2016; PERES et al, 2019).…”

“…Os efeitos da salinização no solo provocam a diminuição da fertilidade físico-química, desestruturação, aumento da densidade aparente e da retenção de água do solo, redução da infiltração de água pelo excesso de íons sódicos; fisiologicamente na planta são afetados a síntese de proteína, metabolismo de lipídieos e fotossíntese, e até mesmo características morfológicas como a taxa de expansão da superfície foliar (DIAS; BLANCO, 2010;AZEVEDO et al, 2018) O estresse salino aciona a síntese de etileno, que impulsiona a liberação de radicais livres e, então, a produção de brassinoesteróides e jasmonatohormônios relacionados ao metabolismo de defesa(ZHU et al, 2016;JIROUTOVA et al, 2018; PERES et al, 2019). Juntamente à liberação de compostos como ascorbato, glutationa, tocoferol, caratenoides e compostos fenólicos e as enzimas superóxido dismutase, catalase, peroxidase do ascorbato e peroxidase de fenóis(BARBOSA et al, 2014;MAIA et al, 2015;ALVES et al, 2016;ZHU et al, 2016; PERES et al, 2019). Neste contexto, a planta "entende6" que o ambiente não está propício ao desenvolvimento de seus descendentes, acionando o sistema de indução de variabilidade intraespecífica, dado principalmente pelo deslocamento do balanço entre ácidos abscísico: GA em favor do ABA (JUNG;PARK, 2011;YUAN et al, 2011;LINKIES;LEUBNER-METZGER, 2012; SHU et al, 2017;VISHAL; KUMAR, 2018), possivelmente devido a uma inibição também da fluridona (fato confirmado para soja;SHU et al, 2017).…”