A NAC Transcription Factor from ‘Sea Rice 86′ Enhances Salt Tolerance by Promoting Hydrogen Sulfide Production in Rice Seedlings

Abstract

Soil salinity severely threatens plant growth and crop performance. Hydrogen sulfide (H2S), a plant signal molecule, has been implicated in the regulation of plant responses to salinity stress. However, it is unclear how the transcriptional network regulates H2S biosynthesis during salt stress response. In this study, we identify a rice NAC (NAM, ATAF and CUC) transcription factor, OsNAC35-like (OsNACL35), from a salt-tolerant cultivar ‘Sea Rice 86′ (SR86) and further show that it may have improved salt tolerance via enhanced H2S production. The expression of OsNACL35 was significantly upregulated by high salinity and hydrogen peroxide (H2O2). The OsNACL35 protein was localized predominantly in the nucleus and was found to have transactivation activity in yeast. The overexpression of OsNACL35 (OsNACL35-OE) in japonica cultivar Nipponbare ramatically increased resistance to salinity stress, whereas its dominant-negative constructs (SUPERMAN repression domain, SRDX) conferred hypersensitivity to salt stress in the transgenic lines at the vegetative stage. Moreover, the quantitative real-time PCR analysis showed that many stress-associated genes were differentially expressed in the OsNACL35-OE and OsNACL35-SRDX lines. Interestingly, the ectopic expression of OsNACL35 triggered a sharp increase in H2S content by upregulating the expression of a H2S biosynthetic gene, OsDCD1, upon salinity stress. Furthermore, the dual luciferase and yeast one-hybrid assays indicated that OsNACL35 directly upregulated the expression of OsDCD1 by binding to the promoter sequence of OsDCD1. Taken together, our observations illustrate that OsNACL35 acts as a positive regulator that links H2S production to salt stress tolerance, which may hold promising utility in breeding salt-tolerant rice cultivar.

A Cationic Amino Acid Transporter NtCAT1 Promotes Leaf Senescence by the Accumulation of ABA in Nicotiana tabacum

“…The homogenates were centrifuged at 12,000× g for 20 min at 4 • C, and the resulting supernatants were used for assays for SOD, POD, and CAT activities. SOD, POD, and CAT activities were measured as previously described [37]. All spectrophotometric values are measured via spectrophotometer (Persee TU-1810, Zhengzhou, China).…”

“…The total chlorophyll contents were measured as described previously [37]. In brief, the rosette leaves from each genotype were cut into sections, flash-frozen with liquid nitrogen, and then stored at −80 • C before used.…”

Tobacco Transcription Factor NtWRKY70b Facilitates Leaf Senescence via Inducing ROS Accumulation and Impairing Hydrogen Sulfide Biosynthesis

“…Studies concerning free radical damage reactions in plant have revealed that reactive oxygen species (ROS) have diverse functions in various developmental and physiological processes, including seed germination, root morphogenesis, stomatal movement, leaf development, and abiotic stress responses [4,18,[26][27][28]. It has been reported that respiratory burst oxidase homologs (Rbohs), as homologs of mammalian NADPH oxidases, participate in accumulation of apoplastic ROS (e.g., O 2 − and H 2 O 2 ), which are targeted to the plasma membrane [29].…”

Optimized extraction technology of glutathione from ‘Haidao 86’ germ rice by response surface methodology

“…Previous reports indicated that the research on sea rice mainly focused on planting, the saline‐alkali tolerance principle, yield improvement, and soil modification (Chen et al, 2017 ; Xie et al, 2021 ). The root system of ‘Haidao 86’ was promoted in low‐salt seawater (3‰), the optimum salinity for seed germination was 3‰, and the maximum salinity tolerance reached 15‰ (Sun et al, 2022 ). Experiments in Xinjiang, Heilongjiang, Guangdong, and other places were successful, among which the unit yield of sea rice in the Xinjiang Kashi saline‐alkali soil experimental field reached 8.24 tons/ha (Wang et al, 2019 ), and the unit yield of sea rice in the Qingdao saline‐alkali soil experimental field reached 10.38 tons/ha (Zhang, 2018 , 2022 ).…”