H2S in Horticultural Plants: Endogenous Detection by an Electrochemical Sensor, Emission by a Gas Detector, and Its Correlation with L-Cysteine Desulfhydrase (LCD) Activity

Abstract

H2S has acquired great attention in plant research because it has signaling functions under physiological and stress conditions. However, the direct detection of endogenous H2S and its potential emission is still a challenge in higher plants. In order to achieve a comparative analysis of the content of H2S among different plants with agronomical and nutritional interest including pepper fruits, broccoli, ginger, and different members of the genus Allium such as garlic, leek, Welsh and purple onion, the endogenous H2S and its emission was determined using an ion-selective microelectrode and a specific gas detector, respectively. The data show that endogenous H2S content range from pmol to μmol H2S · g−1 fresh weight whereas the H2S emission of fresh-cut vegetables was only detected in the different species of the genus Allium with a maximum of 9 ppm in garlic cloves. Additionally, the activity and isozymes of the L-cysteine desulfhydrase (LCD) were analyzed, which is one of the main enzymatic sources of H2S, where the different species of the genus Allium showed the highest activities. Using non-denaturing gel electrophoresis, the data indicated the presence of up to nine different LCD isozymes from one in ginger to four in onion, leek, and broccoli. In summary, the data indicate a correlation between higher LCD activity with the endogenous H2S content and its emission in the analyzed horticultural species. Furthermore, the high content of endogenous H2S in the Allium species supports the recognized benefits for human health, which are associated with its consumption.

H2S-Generating Cytosolic L-Cysteine Desulfhydrase and Mitochondrial D-Cysteine Desulfhydrase from Sweet Pepper (Capsicum annuum L.) Are Regulated During Fruit Ripening and by Nitric Oxide

“…Table 1 shows the identified proteins that can generate H 2 S from the two cysteines (Cys) isomers, either L-cysteine (L-Cys) or D-Cys. Thus, we focus on the cytosolic LCD and the mitochondrial DCD that are considered the main sources of H 2 S in higher plants (Mei et al, 2019 ; Muñoz-Vargas et al, 2022 ; Scuffi et al, 2014 ; Yamasaki et al, 2019 ).…”

“…The LCD is considered the main source of H 2 S and catalyzes the following reaction: L-cysteine + H 2 O → pyruvate + NH 4 + + H 2 S + H + , requiring pyridoxal 5′-phosphate (PLP) as a cofactor (Kurmanbayeva et al, 2022 ; Muñoz-Vargas et al, 2022 ). LCD participates in diverse physiological processes such as root development (Mei et al, 2019 ), stomatal closure (Ma et al, 2021 ; Scuffi et al, 2014 ; Shen et al, 2020 ), leaf senescence (Hu et al, 2021 ), fruit ripening (Hu et al, 2020 ; Muñoz-Vargas et al, 2018 ), but also in the mechanism of response to diverse environmental stresses (Kaya, 2020 ; Kharbech et al, 2022 ; Sun et al, 2022 ; Wang et al, 2022 ; Wang et al, 2023 ; Zhou et al, 2021 ).…”

Role of Acetic Acid and Nitric Oxide against Salinity and Lithium Stress in Canola (Brassica napus L.)

“…On the other hand, the results of PCA levels indicated stronger positive associations between NO- or AA-primed stressed plants and the content of this signaling molecule than those observed under stress conditions. Numerous studies have confirmed the functional parallelism of NO and H 2 S in mediating multiple physiological pathways under harsh conditions [ 106 ]. Many investigations have deduced the involvement of H 2 S in NO-mediated salinity or heavy metal stresses of many plants [ 107 , 108 , 109 ], which supports the role of NO, or possibly AA, in the mitigation of salinity and/or Li stress through the upregulation of endogenous H 2 S.…”

Sodium nitroprusside modulates oxidative and nitrosative processes in Lycopersicum esculentum L. under drought stress

“…The interaction between NO and H 2 S may lead to modifications in protein function and signaling pathways, which are essential for the plant’s adaptation to water scarcity. The role of L-DES in mediating the production of H 2 S from l -cysteine has been recognized as a significant factor in plant stress physiology (Shen et al 2019 ; Muñoz-Vargas et al 2022 ). Furthermore, the interplay between NO and H 2 S has been shown to involve various post-translational modifications, including S-nitrosylation and persulfidation, which affect protein activity and cellular signaling under stress conditions (Aroca et al 2018 ; Singh et al 2022 ).…”