TY - JOUR
T1 - Mechanism enhancing arabidopsis resistance to cadmium
T2 - The role of NRT1.5 and proton pump
AU - Wang, Tao
AU - Hua, Yingpeng
AU - Chen, Moxian
AU - ZHANG, Jianhua
AU - Guan, Chunyun
AU - Zhang, Zhenhua
N1 - Funding Information:
We thank Dr. Abdelbagi M. Ismail (IRRI) discussed the MS contents, and thank The Chinese University of Hong Kong supplied the plant materials mutant (bglu10 and bglu18 ). Funding. This study was financially supported in part by the National Key R&D Program of China (2017YFD0200100 and 2017YFD0200103), the Hunan Provincial Recruitment Program of Foreign Experts, the National Oilseed Rape Production Technology System of China, “2011 Plan” supported by The Chinese Ministry of Education, and the Double First-Class Construction Project of Hunan Agricultural University (kxk201801005).
PY - 2018
Y1 - 2018
N2 - Aim: Heavy metal pollution is serious in China, and abscisic acid (ABA) is an important stress hormone. How it regulates plant tolerance to cadmium remains unclear, so we aimed to explore the molecular mechanism responsible for enhanced cadmium resistance in Arabidopsis wild-type and mutant plants and Brassica napus seedlings. Methods: Arabidopsis/B. napus were cultured hydroponically for 28/15 days and then treated with 20/10 μM Cd/Cd+ABA (5 μM) for 3/4 days. Chlorophyll degradation rate, SPAD values, proline, MDA, ABA, (Formula presented.), and Cd concentrations were measured in root vacuoles and protoplasts; root to shoot (Formula presented.) and Cd concentration ratios were determined and NRT1.5-, NRT1.8-, BnNRT1.5-, and BnNRT1.8-related gene expression was studied. Results: Cytoplasmic ABA levels in root cells of bglu10 and bglu18 Arabidopsis mutants were significantly lower than those in the wild-type, apparently making the latter more resistant to Cd. (Formula presented.) long-distance transporter NRT1.5 responded to ABA signaling by downregulating its own expression, while NRT1.8 did not respond. Concomitantly, proton pump activity in wild-type plants was higher than in the bglu10 and bglu18 mutants; thus, more (Formula presented.) and Cd accumulated in the vacuoles of wild-type root cells. ABA application inhibited Cd absorption by B. napus. BnNRT1.5 responded to exogenous ABA signal by downregulating its own expression, while the lack of response by BnNRT1.8 resulted in increased amount of (Formula presented.) accumulating in the roots to participate in the anti-cadmium reaction. Conclusion: NRT1.5 responds to the ABA signal to inhibit its own expression, whereas unresponsiveness of NRT1.8 causes accumulation of (Formula presented.) in the roots; thus, enhancing Cd resistance. In Arabidopsis, because of proton pump action, more (Formula presented.) and Cd accumulate in the vacuoles of Arabidopsis root cells, thereby reducing damage by Cd toxicity. However, in B. napus, the addition of exogenous ABA inhibited Cd absorption. Our data provide a sound basis to the theoretical molecular mechanism involved in hormone signaling during response of plants to heavy metal stress.
AB - Aim: Heavy metal pollution is serious in China, and abscisic acid (ABA) is an important stress hormone. How it regulates plant tolerance to cadmium remains unclear, so we aimed to explore the molecular mechanism responsible for enhanced cadmium resistance in Arabidopsis wild-type and mutant plants and Brassica napus seedlings. Methods: Arabidopsis/B. napus were cultured hydroponically for 28/15 days and then treated with 20/10 μM Cd/Cd+ABA (5 μM) for 3/4 days. Chlorophyll degradation rate, SPAD values, proline, MDA, ABA, (Formula presented.), and Cd concentrations were measured in root vacuoles and protoplasts; root to shoot (Formula presented.) and Cd concentration ratios were determined and NRT1.5-, NRT1.8-, BnNRT1.5-, and BnNRT1.8-related gene expression was studied. Results: Cytoplasmic ABA levels in root cells of bglu10 and bglu18 Arabidopsis mutants were significantly lower than those in the wild-type, apparently making the latter more resistant to Cd. (Formula presented.) long-distance transporter NRT1.5 responded to ABA signaling by downregulating its own expression, while NRT1.8 did not respond. Concomitantly, proton pump activity in wild-type plants was higher than in the bglu10 and bglu18 mutants; thus, more (Formula presented.) and Cd accumulated in the vacuoles of wild-type root cells. ABA application inhibited Cd absorption by B. napus. BnNRT1.5 responded to exogenous ABA signal by downregulating its own expression, while the lack of response by BnNRT1.8 resulted in increased amount of (Formula presented.) accumulating in the roots to participate in the anti-cadmium reaction. Conclusion: NRT1.5 responds to the ABA signal to inhibit its own expression, whereas unresponsiveness of NRT1.8 causes accumulation of (Formula presented.) in the roots; thus, enhancing Cd resistance. In Arabidopsis, because of proton pump action, more (Formula presented.) and Cd accumulate in the vacuoles of Arabidopsis root cells, thereby reducing damage by Cd toxicity. However, in B. napus, the addition of exogenous ABA inhibited Cd absorption. Our data provide a sound basis to the theoretical molecular mechanism involved in hormone signaling during response of plants to heavy metal stress.
KW - ABA signaling
KW - Cd stress
KW - NO
KW - NRT1.5
KW - NRT1.8
KW - Proton pump activity
UR - http://www.scopus.com/inward/record.url?scp=85058794602&partnerID=8YFLogxK
U2 - 10.3389/fpls.2018.01892
DO - 10.3389/fpls.2018.01892
M3 - Journal article
AN - SCOPUS:85058794602
SN - 1664-462X
VL - 871
JO - Frontiers in Plant Science
JF - Frontiers in Plant Science
M1 - 1892
ER -