Comparative Profiles of Gene Expression in Leaves and Roots of Maize Seedlings under Conditions of Salt Stress and the Removal of Salt Stress

Abstract

We studied the transcriptional profiles of leaves and roots of three-leaf stage seedlings of the maize inbred line YQ7-96 under conditions of salt stress (100 mM NaCl) and removal of salt stress (RSS). A total of 296 genes were regulated specifically by the stress, of which 206 were specific to leaves and 90 were specific to roots. Stress-regulated genes were classified into eight and seven expression patterns for leaves and roots, respectively. There were 60 genes which were regulated specifically by RSS, 27 of which were specific to leaves and 33 specific to roots. No genes were found to be co-regulated in tissues and to be regulated commonly by the stress and RSS. It can be concluded that (i) at the early stage of the stress, transcriptional responses are directed at water deficit in maize leaves but at both water deficit and Na+ accumulation in roots; (ii) at the later stage, the responses in leaves and roots result from dual effects of both water deficit and Na+ accumulation; (iii) the polyamine metabolic pathway is an important linker for the co-ordination between leaves and roots to accomplish the tolerance of the whole maize plant to the stress; (iv) the stress can lead to genomic restructuring and nuclear transport in maize; (v) maize leaves are distinct from roots in terms of molecular mechanisms for responses to and growth recovery from the stress; and (vi) mechanisms for the maize responses to the stress differ from those for their growth recovery during RSS.

An ordered EST catalogue and gene expression profiles of cassava (Manihot esculenta) at key growth stages

“…cDNA library construction Cassava cDNA library construction followed the method previously described (Qing et al 2009) using mRNA isolated from the cassava roots at 200 DAP. Approximately 500 ng of mRNA were used to synthesize the first-strand cDNA by reverse transcription with primers 5 0 -AACATA TGCGGCCGCATTATGGCCGGG-3 0 and 5 0 -GATCTTC CACGCGTCGAC(T)30(AGC)(ATGC)-3 0 ), in a reaction mix containing 400 units of SuperScriptTM III RNase H -(Invitrogen, Carlsbad, CA, USA).…”

“…Amplification of cDNA inserts cDNA inserts were amplified by PCR from the bacterial clones following the established method (Qing et al 2009). …”

Inhibition of phospholipase C disrupts cytoskeletal organization and gravitropic growth in Arabidopsis roots

“…Overcompensation in root growth has been observed in maize during recovery from drought stress (Dekankova et al 2004) and in gene expression in maize during recovery from salinity stress (Qing et al 2009). The mechanism is unclear.…”

“Omics” of Maize Stress Response for Sustainable Food Production: Opportunities and Challenges

“…The transcriptional profiles of maize leaves and roots under salt stress have been analyzed (Qing et al, 2009). In total, 296 genes were found to be regulated specifically by salt stress in leaves and roots.…”

“…In total, 296 genes were found to be regulated specifically by salt stress in leaves and roots. The primary effects of salt stress on cellular function included catalytic activity, nucleic acid binding, protein binding, and structural molecule activity (Qing et al, 2009). In addition, the genes whose levels clearly changed under salt stress or that were specific were selected for future analysis.…”