A Cold-Shock Protein from the South Pole-Dwelling Soil Bacterium Arthrobacter sp. Confers Cold Tolerance to Rice.

So Young Kim,Kyung Do Kim,Kyong Mi Jun,Yeon-Ki Kim,Woosuk Cho,Gang-Seob Lee,Xiaoxuan Du,Joung Sug Kim

doi:10.3390/genes12101589

Abstract

Low temperature is a critical environmental factor restricting the physiology of organisms across kingdoms. In prokaryotes, cold shock induces the expression of various genes and proteins involved in cellular processes. Here, a cold-shock protein (ArCspA) from the South Pole-dwelling soil bacterium Arthrobacter sp. A2-5 was introduced into rice, a monocot model plant species. Four-week-old 35S:ArCspA transgenic rice plants grown in a cold chamber at 4 °C survived for 6 days. Cold stress significantly decreased the chlorophyll content in WT plants after 4 days compared with that in 35S:ArCspA transgenic plants. RNA-seq analysis was performed on WT and 35S:ArCspA transgenic rice with/without cold stress. GO terms such as “response to stress (GO:0006950)”, “response to cold (GO:0009409)”, and “response to heat (GO:0009408)” were significantly enriched among the upregulated genes in the 35S:ArCspA transgenic rice under normal conditions, even without cold-stress treatment. The expression of five cold stress-related genes, Rab16B (Os11g0454200), Rab21 (Os11g0454300), LEA22 (Os01g0702500), ABI5 (Os01 g0859300), and MAPK5 (Os03g0285800), was significantly upregulated in the transgenic rice compared with the WT rice. These results indicate that the ArCspA gene might be involved in the induction of cold-responsive genes and provide cold tolerance.

Highlights

Organisms have evolved elaborate mechanisms to cope with abiotic stresses such as dehydration, heat shock and low-temperature stress
To test the effects of Arthrobacter sp. A2-5 (ArCspA) in rice, plants were transformed with a vector harboring ArCspA under the control of the CaMV 35S promoter [29]
The transgenic plants recovered much better than the WT plants did under normal temperature after cold stress (Figure 3). These results showed that the constitutive expression of ArCspA increases the tolerance of rice to cold stress

Summary

Introduction

Organisms have evolved elaborate mechanisms to cope with abiotic stresses such as dehydration, heat shock and low-temperature stress. Low temperature is a critical environmental factor that restricts the growth and development of many plant species, including rice [1]. Under chilling-stress conditions, stomatal conductance, photosynthesis, growth and, productivity are hindered due to the solidification of membrane lipids and, the deactivation of carriermediated transport and enzyme-mediated processes [3]. If plants are exposed to freezing conditions, the damage is even more severe because osmotic stress-induced dehydration causes ice crystals to form in the cell walls. Under these conditions, plants are exposed to stresses that are very similar to stresses caused by water deficit and mechanical processes

Methods

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Discussion

Conclusion