Transcriptional Regulatory Components Responding to Macronutrient Limitation

Abstract

The mechanisms of how plants sense nutrient availability in soils and then send the signals through downstream signal cascades are essential processes for plant survival. Although understanding the regulatory mechanisms of macronutrient sensing and signaling are very important, many components still remain unknown. This review describes the recent progress in identifying the transcriptional regulatory components that respond to phosphorus, nitrogen, potassium, and sulfur limitation. Under phosphorus limited conditions, a MYB transcription factor, PHR1, functions as a key transcriptional regulator of the phosphorus deficient responsive genes via binding to the P1BS cis element. Similarly, SLIM1 plays crucial roles in the expression of the sulfur starved responsive genes through binding to the sulfur responsive cis element. The nitrogen deficient responsive MYB transcription factors control nitrogen metabolism. Cytokinins and microRNAs (miRNAs) also mediate macronutrient metabolic processes. Much less is known about the potassium deficient signaling components, as compared to the other nutrient signaling pathways. Multiple recent studies have suggested that phytohormones, such as ethylene, auxin, jasmonic acid, and abscisic acid (ABA), and reactive oxygen species (ROS) play roles as transcriptional regulatory components in potassium deficient signaling.

Chromosomal localization of selected SCARs converted from new RAPD, ISSR and R-ISSR markers linked to rye (Secale cereale L.) tolerance to nutrient deprivation stress identified using bulk segregant analysis

“…According to a study by Nieves-Cordones et al (2008), also root plasma membrane potential may be involved in transcription regulation of HAK5. Also CIPK23 protein kinase plays an important role in systemic response to deficiency of this element, which confirms the significant role of calcium in the potassium deficiency signaling pathway and its influence on activation of AKT1 potassium channels, as well as a range of hormones with significant part of not only above-mentioned ethylene but also auxins, jasmonic acid or ABA (Shin, 2011).…”

“…ACC synthases produce ACC, which is converted into ethylene by ACC oxidases (Faris et al 2001). According to Faris et al (2001), Jung et al (2009Shin (2011), ethylene biosynthesis and ethylene signaling interact at the different levels with the plant's response to potassium, such as nitrogen deprivations, or up-or down-regulating the expression of their transcription factor genes. One such gene has been identified in this experiment as an annotation (AP009567.1 -5e-127) for one molecular marker (SCAR) -Xscszm27.…”

“…acetyl-CoA oxidase or putative ethylene-responsive transcription factors (ERF). The differences may be significant since they are often subjected to regulation by miRNA (Kuo and Chiou, 2011;Shin, 2011;Schachtman, 2012), and for genes engaged in N uptake and assimilation by nitrate responsive cis-acting elements (Hu et al 2009). …”

“…Also, the gene encoding miR393 is upregulated, significantly affecting expression (down regulate) of the auxin receptor -gene AFB3 (auxin signaling Fbox 3) through its transcript digestion. Thus, root growth is inhibited (Vidal et al 2010;Shin, 2011;Schachtman, 2012).…”

Sulphur responsiveness of the Chlamydomonas reinhardtii LHCBM9 promoter

“…This supported the findings of previous work, where the LHCBM9 gene was not found to be up-regulated upon N deprivation Miller et al 2007;Moseley et al 2009), but contradicted a recent study by Grewe et al (2014), who found that N deprivation induced LHCBM9 protein expression. It is possible that LHCBM9 is regulated by N deprivation at a level other than transcription, especially since N-dependent gene regulation shares regulatory elements with the S-response pathway (Kopriva and Rennenberg 2004;Shin 2011). Alternatively, S deprivation may be required before responses to other nutrients can be seen; confirmation of this would require combined nutrient deprivation experiments.…”