Role of Stomatal Conductance in Modifying the Dose Response of Stress-Volatile Emissions in Methyl Jasmonate Treated Leaves of Cucumber (Cucumis Sativa)

Abstract

Treatment by volatile plant hormone methyl jasmonate (MeJA) leads to release of methanol and volatiles of lipoxygenase pathway (LOX volatiles) in a dose-dependent manner, but how the dose dependence is affected by stomatal openness is poorly known. We studied the rapid (0–60 min after treatment) response of stomatal conductance (Gs), net assimilation rate (A), and LOX and methanol emissions to varying MeJA concentrations (0.2–50 mM) in cucumber (Cucumis sativus) leaves with partly open stomata and in leaves with reduced Gs due to drought and darkness. Exposure to MeJA led to initial opening of stomata due to an osmotic shock, followed by MeJA concentration-dependent reduction in Gs, whereas A initially decreased, followed by recovery for lower MeJA concentrations and time-dependent decline for higher MeJA concentrations. Methanol and LOX emissions were elicited in a MeJA concentration-dependent manner, whereas the peak methanol emissions (15–20 min after MeJA application) preceded LOX emissions (20–60 min after application). Furthermore, peak methanol emissions occurred earlier in treatments with higher MeJA concentration, while the opposite was observed for LOX emissions. This difference reflected the circumstance where the rise of methanol release partly coincided with MeJA-dependent stomatal opening, while stronger stomatal closure at higher MeJA concentrations progressively delayed peak LOX emissions. We further observed that drought-dependent reduction in Gs ameliorated MeJA effects on foliage physiological characteristics, underscoring that MeJA primarily penetrates through the stomata. However, despite reduced Gs, dark pretreatment amplified stress-volatile release upon MeJA treatment, suggesting that increased leaf oxidative status due to sudden illumination can potentiate the MeJA response. Taken together, these results collectively demonstrate that the MeJA dose response of volatile emission is controlled by stomata that alter MeJA uptake and volatile release kinetics and by leaf oxidative status in a complex manner.

KETAHANAN BEBERAPA GENOTIPE PADI HARAPAN TERHADAP PENYAKIT HAWAR DAUN BAKTERI (Xanthomonas oryzae pv. oryzae) STRAIN III, IV DAN VIII.

“…Proses masuknya mikroba ke dalam jaringan tanaman sedikitnya terjadi melalui tiga cara, yaitu mencerna dinding sel, masuk melalui bagian yang terluka, dan menyerang melalui bukaan alami seperti stomata (Ed-har et al, 2017). Dalam kasus ini, bakteri masuk melalui pelukaan daun yang menginduksi terbukanya stomata (Jiang et al, 2019).…”

Bioregulators Induced Modulation of Leaf Physiological Attributes and Severity of Papaya Ring Spot Viral Disease Symptom expression in Papaya

“…Among different bioregulators, plants treated with methyl jasmonate recorded lower stomatal conductance. It is known that plants exposed to methyl jasmonate resulted in stomatal closure and reduced stomatal conductance, leading to reduced leaf photosynthesis due to limited CO 2 availability (Jiang et al, 2020;Jung, 2004 andAttaran et al, 2014).…”

Transpiration Responses to Potential Volatile Signals and Hydraulic Failure in Single Leaves of Vitis Vinifera (Cv. Shiraz) and Arabidopsis Thaliana (Col 0) Utilising Sensitive Liquid Flow and Simultaneous Gas Exchange.

“…By regulating the aperture of stomata, plants adjust transpiration and the intake of CO 2 for photosynthesis when responding to various factors (Hetherington & Woodland, 2003) such as water availability (Buckley, 2019;Hernandez-Santana, Rodriguez-Dominguez, Fernández, & Diaz-Espejo, 2016;Tombesi et al, 2015), temperature (Urban, Ingwers, McGuire, & Teskey, 2017;von Caemmerer & Evans, 2015), light (Inoue & Kinoshita, 2017;Shimazaki, Doi, Assmann, & Kinoshita, 2007), CO 2 concentration (Engineer et al, 2016;Israelsson et al, 2006), biotic stress (Melotto, Underwood, Koczan, Nomura, & He, 2006) and volatile organic compounds (VOCs) in the atmosphere (Jiang, Ye, Rasulov, & Niinemets, 2020;Niinemets & Reichstein, 2003). They are also the pathway for the release of some VOCs including simple small molecules such as methanol (Hüve et al, 2007).…”