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OsAUX 1 controls lateral root initiation in rice ( O ryza sativa L .)
Author(s) -
Zhao Heming,
Ma Tengfei,
Wang Xin,
Deng Yingtian,
Ma Haoli,
Zhang Rongsheng,
Zhao Jie
Publication year - 2015
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.12467
Subject(s) - auxin , lateral root , polar auxin transport , primordium , gravitropism , mutant , microbiology and biotechnology , arabidopsis , biology , indole 3 acetic acid , chemistry , gene , biochemistry
Polar auxin transport, mediated by influx and efflux transporters, controls many aspects of plant growth and development. The auxin influx carriers in A rabidopsis have been shown to control lateral root development and gravitropism, but little is known about these proteins in rice. This paper reports on the functional characterization of OsAUX 1 . Three OsAUX 1 T ‐ DNA insertion mutants and RNAi knockdown transgenic plants reduced lateral root initiation compared with wild‐type ( WT ) plants. OsAUX 1 overexpression plants exhibited increased lateral root initiation and OsAUX 1 was highly expressed in lateral roots and lateral root primordia. Similarly, the auxin reporter, DR 5‐ GUS , was expressed at lower levels in osaux 1 than in the WT plants, which indicated that the auxin levels in the mutant roots had decreased. Exogenous 1‐naphthylacetic acid ( NAA ) treatment rescued the defective phenotype in osaux 1‐1 plants, whereas indole‐3‐acetic acid ( IAA ) and 2,4‐ D could not, which suggested that OsAUX 1 was a putative auxin influx carrier. The transcript levels of several auxin signalling genes and cell cycle genes significantly declined in osaux 1 , hinting that the regulatory role of OsAUX 1 may be mediated by auxin signalling and cell cycle genes. Overall, our results indicated that OsAUX 1 was involved in polar auxin transport and functioned to control auxin‐mediated lateral root initiation in rice.