A defensin-like protein drives cadmium efflux and allocation in rice

Luo, Jin-Song; Huang, Jing; Zeng, Da Li; Peng, Jia-Shi; Zhang, Guo Bin; Lü, Hai; Yuan, Guohui; Yi, Hong; Fu, Yan; Han, Bin; Lin, Hong; Qian, Qian; Gong, Ji-Ming

doi:10.1038/s41467-018-03088-0

Cited by 298 publications

(205 citation statements)

References 51 publications

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“…Cd is a highly toxic environmental contaminant. Organisms are equipped with Cd detoxification mechanisms, such as extrusion, chelation, and compartmentalization (Wysocki and Tamás, 2010;Wei et al, 2014;Luo et al, 2018). Yeast ATX1 was reported to chelate Cd 2+ as well as Cu + (Pufahl et al, 1997;Heo et al, 2012).…”

Section: Overexpression Of Osatx1 Increases CD Accumulation In the Shmentioning

confidence: 99%

OsATX1 Interacts with Heavy Metal P1B-Type ATPases and Affects Copper Transport and Distribution

et al. 2018

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Copper (Cu) is an essential micronutrient for plant growth. However, the molecular mechanisms underlying Cu trafficking and distribution to different organs in rice () are poorly understood. Here, we report the function and role of Antioxidant Protein1 (OsATX1), a Cu chaperone in rice. Knocking out resulted in increased Cu concentrations in roots, whereas overexpression reduced root Cu concentrations but increased Cu accumulation in the shoots. At the reproductive stage, the concentrations of Cu in developing tissues, including panicles, upper nodes and internodes, younger leaf blades, and leaf sheaths of the main tiller, were increased significantly in -overexpressing plants and decreased in mutants compared with the wild type. The mutants also showed a higher Cu concentration in older leaves. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that OsATX1 interacts with the rice heavy metal P-ATPases HMA4, HMA5, HMA6, and HMA9. These results suggest that OsATX1 may function to deliver Cu to heavy metal P-ATPases for Cu trafficking and distribution in order to maintain Cu homeostasis in different rice tissues. In addition, heterologous expression of in the yeast () cadmium-sensitive mutant Δ increased the tolerance to Cu and cadmium by decreasing their respective concentrations in the transformed yeast cells. Taken together, our results indicate that OsATX1 plays an important role in facilitating root-to-shoot Cu translocation and the redistribution of Cu from old leaves to developing tissues and seeds in rice.

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Section: Overexpression Of Osatx1 Increases CD Accumulation In the Shmentioning

confidence: 99%

OsATX1 Interacts with Heavy Metal P1B-Type ATPases and Affects Copper Transport and Distribution

et al. 2018

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“…Sequencing and annotation studies identified thousands of plant defensins in rice (Kawahara et al, 2013). The quantitative trait locus of Cd accumulation in rice leaf 1 (CAL1) was mapbased cloned and was found to encode a defensin-like protein (Luo et al, 2018). CAL1 was functionally characterized as a positive regulator of Cd accumulation in rice leaves (Luo et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Overexpression of a Defensin-Like Gene CAL2 Enhances Cadmium Accumulation in Plants

et al. 2020

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Accumulation and detoxification of cadmium in rice shoots are of great importance for adaptation to grow in cadmium contaminated soils and for limiting the transport of Cd to grains. However, the molecular mechanisms behind the processes involved in this regulation remain largely unknown. Defensin proteins play important roles in heavy metal tolerance and accumulation in plants. In rice, the cell wall-localized defensin protein (CAL1) is involved in Cd efflux and partitioning to the shoots. In the present study, we functionally characterized the CAL2 defensin protein and determined its contribution to Cd accumulation. CAL2 shared 66% similarity with CAL1, and its mRNA accumulation is mainly observed in roots and is unaffected by Cd stress, but its transcription level was lower than that of CAL1 based on the relative expression of CAL2/Actin1 observed in this study and that reported previously. A promoter-GUS assay revealed that CAL2 is expressed in root tips. Stable expression of the CAL2-mRFP fusion protein indicated that CAL2 is also localized in the cell walls. An in vitro Cd binding experiment revealed that CAL2 has Cd chelation activity. Overexpression of CAL2 increased Cd accumulation in Arabidopsis and rice shoots, but it had no effect on the accumulation of other essential elements. Heterologous expression of CAL2 enhanced Cd sensitivity in Arabidopsis, whereas overexpression of CAL2 had no effect on Cd tolerance in rice. These findings indicate that CAL2 positively regulates Cd accumulation in ectopic overexpression lines of Arabidopsis and rice. We have identified a new gene regulating Cd accumulation in rice grain, which would provide a new genetic resource for molecular breeding.

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“…Several of the transporters involved in plant Cd accumulation have been identified, including, in Arabidopsis and rice: IRT1 (iron‐regulated transporter), Nramp1 (natural resistance‐associated macrophage protein) and OsNramp5 for Cd uptake, HMA3 (heavy metal ATPase) for Cd sequestration into vacuoles, AtNRAMP3/4 for Cd transport from vacuoles, HMA2, AtHMA4, OsLCT1 (low‐affinity cation transporter), and OsCAL1 (Cd accumulation in leaf) for Cd translocation and distribution (Mendoza‐Cozatl et al ; Clemens and Ma ; Luo et al ). Some signaling pathways, such as those for reactive oxygen species (ROS), nitric oxide (NO), gibberellin and auxin, have been reported to be involved in the transcriptional regulation of relevant transporter genes (Rodriguez‐Serrano et al ; Gallego et al ; Zhu et al ; Zhu et al ; Kawakami and Bhullar ), such as the gene encoding IRT1.…”

Section: Introductionmentioning

confidence: 99%

Jasmonic acid alleviates cadmium toxicity in Arabidopsis via suppression of cadmium uptake and translocation

Lei

Sun

et al. 2019

JIPB

106

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Jasmonic acid (JA) is thought to be involved in plant responses to cadmium (Cd) stress, but the underlying molecular mechanisms are poorly understood. Here, we show that Cd treatment rapidly induces the expression of genes promoting endogenous JA synthesis, and subsequently increases the JA concentration in Arabidopsis roots. Furthermore, exogenous methyl jasmonate (MeJA) alleviates Cd‐generated chlorosis of new leaves by decreasing the Cd concentration in root cell sap and shoot, and decreasing the expression of the AtIRT1, AtHMA2 and AtHMA4 genes promoting Cd uptake and long‐distance translocation, respectively. In contrast, mutation of a key JA synthesis gene, AtAOS, greatly enhances the expression of AtIRT1, AtHMA2 and AtHMA4, increases Cd concentration in both roots and shoots, and confers increased sensitivity to Cd. Exogenous MeJA recovers the enhanced Cd‐sensitivity of the ataos mutant, but not of atcoi1, a JA receptor mutant. In addition, exogenous MeJA reduces NO levels in Cd‐stressed Arabidopsis root tips. Taken together, our results suggest that Cd‐induced JA acts via the JA signaling pathway and its effects on NO levels to positively restrict Cd accumulation and alleviates Cd toxicity in Arabidopsis via suppression of the expression of genes promoting Cd uptake and long‐distance translocation.

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A defensin-like protein drives cadmium efflux and allocation in rice

Cited by 298 publications

References 51 publications

OsATX1 Interacts with Heavy Metal P1B-Type ATPases and Affects Copper Transport and Distribution

OsATX1 Interacts with Heavy Metal P1B-Type ATPases and Affects Copper Transport and Distribution

Overexpression of a Defensin-Like Gene CAL2 Enhances Cadmium Accumulation in Plants

Jasmonic acid alleviates cadmium toxicity in Arabidopsis via suppression of cadmium uptake and translocation

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