Changes in Transcript Related to Osmosis and Intracellular Ion Homeostasis in Paulownia tomentosa under Salt Stress

Abstract

Paulownia tomentosa is an important economic and greening tree species that is cultivated widely, including salt environment. Our previous studies indicated its autotetraploid induced by colchicine showed better stress tolerance, but the underlying molecular mechanism related to ploidy and salt stress is still unclear. To investigate this issue, physiological measurements and transcriptome profiling of diploid and autotetraploid plants untreated and treated with NaCl were performed. Through the comparisons among four accessions, for one thing, we found different physiological changes between diploid and autotetraploid P. tomentosa; for another, and we detected many differentially expressed unigenes involved in salt stress response. These differentially expressed unigenes were assigned to several metabolic pathways, including “plant hormone signal transduction,” “RNA transporter,” “protein processing in endoplasmic reticulum,” and “plant-pathogen interaction,” which constructed the complex regulatory network to maintain osmotic and intracellular ion homeostasis. Quantitative real-time polymerase chain reaction was used to confirm the expression patterns of 20 unigenes. The results establish the foundation for the genetic basis of salt tolerance in P. tomentosa, which in turn accelerates Paulownia breeding and expands available arable land.

Indole-3-acetic acid improves drought tolerance of white clover via activating auxin, abscisic acid and jasmonic acid related genes and inhibiting senescence genes

“…Xiong found that the over-expression of MYB48-1 promoted biosynthesis of ABA and improved drought resistance of transgenic rice [29]. AtMYB60 regulated stomatal movement and promoted Arabidopsis thaliana to respond to drought stress [66]. Different MYBs showed varied functions in the progress of responding to drought and improved drought resistance.…”

Indole -3-acetic acid improves drought tolerance of white clover via activating auxin, abscisic acid and jasmonic acid related genes and inhibiting senescence genes

“…Our studies found that both exogenous IAA and drought stressregulated expression of MYB14 and MYB48 and L-AOPP decreased their expressions (Figure 4G, 4H).Xiong found that the over-expression of MYB48-1 promoted biosynthesis of ABA and improved drought resistance of transgenic rice[30]. AtMYB60 regulated stomatal movement and promoted Arabidopsis thaliana to respond to drought stress[67]. Different MYBs showed varied functions in the progress of responding to drought and improved drought resistance.…”

Indole -3-acetic acid improves drought tolerance of white clover associated with activating auxin-related genes, abscisic acid and jasmonic acid-induced stress responsive transcription factors, and inhibiting senescence genes

“…bZIP37 expressed highly in the salt-stressed plant, which might effectively activated downstream of ABA-inducible gene expression [64]. We found that expression of bZIP11 was also induced by exogenous IAA (Figure 4A), and that of bZIP37 was induced by PEG-6000 stress ( Figure 4B).…”