The AaERF64-AaTPPA module participates in cold acclimatization of Actinidia arguta (Sieb. et Zucc.) Planch ex Miq.

Actinidia arguta (A. arguta, kiwiberry) is a perennial deciduous vine with a strong overwintering ability. We hypothesized that trehalose metabolism, which plays a pivotal role in the stress tolerance of plants, may be involved in the cold acclimatization of A. arguta. Transcriptome analysis showed that the expression of AaTPPA, which encodes a trehalose-6-phosphate phosphatase (TPP), was upregulated in response to low temperatures. AaTPPA expression levels were much higher in lateral buds, roots, and stem cambia than in leaves in autumn. In AaTPPA-overexpressing (OE) Arabidopsis thaliana (A. thaliana), trehalose levels were 8-11 times higher than that of the wild type (WT) and showed different phenotypic characteristics from WT and OtsB (Escherichia coli TPP) overexpressing lines. AaTPPA-OE A. thaliana exhibited significantly higher freezing tolerance than WT and OtsB-OE lines. Transient overexpression of AaTPPA in A. arguta leaves increased the scavenging ability of reactive oxygen species (ROS) and the soluble sugar and proline contents. AaERF64, an ethylene-responsive transcription factor, was induced by ethylene treatment and bound to the GCC-box of the AaTPPA promoter to activate its expression. AaTPPA expression was also induced by abscisic acid. In summary, the temperature decrease in autumn is likely to induce AaERF64 expression through an ethylene-dependent pathway, which consequently upregulates AaTPPA expression, leading to the accumulation of osmotic protectants such as soluble sugars and proline in the overwintering tissues of A. arguta. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-024-01475-8.

Pyrite bio-leachate, mine wastewater can sterilize the rice (Oryza sativa L.) seeds and promote the germination.

We developed the way to use pyrite bio-leachate (PBL), the wastewater of bioleaching of refractory gold ore in agriculture. PBL contains high amount of iron and at certain concentration, iron has toxicity on microorganisms. Therefore PBL can be used for rice seed sterilization. Method 1 is soaking rice seeds in 100%, 10%, and 2% PBL for 1, 2, 3, and 4 days (25℃) and drying them. Method 2 is soaking rice seeds in 100%, 10%, and 2% PBL for 30 min, 60 min, and 120 min (25℃), wetting for 2 days under the shade and drying for 5 days. Method 1 with 100%, 10%, and 2% PBL did not sterilize rice seeds completely. Method 2 with 100% and 10% PBL showed the complete sterilization effect and enhanced the germination of rice seeds in any soaking time. Similar results were achieved in seedbed experiments. PBL which has serious potential to pollute the environment can be used for rice seed sterilization. Soaking rice seeds in 100% and 10% PBL for 30 min, 60 min, and 120 min (25℃), wetting for 2 days under the shade and drying them for 5 days, can sterilize the rice seeds completely and enhance the germination.