The Barley Heavy Metal Associated Isoprenylated Plant Protein HvFP1 Is Involved in a Crosstalk between the Leaf Development and Abscisic Acid-Related Drought Stress Responses

Abstract

The heavy metal associated isoprenylated plant proteins (HIPPs) are characterized by at least one heavy metal associated (HMA) domain and a C-terminal isoprenylation motif. Hordeum vulgare farnesylated protein 1 (HvFP1), a barley HIPP, is upregulated during drought stress, in response to abscisic acid (ABA) and during leaf senescence. To investigate the role of HvFP1, two independent gain-of-function lines were generated. In a physiological level, the overexpression of HvFP1 results in the delay of normal leaf senescence, but not in the delay of rapid, drought-induced leaf senescence. In addition, the overexpression of HvFP1 suppresses the induction of the ABA-related genes during drought and senescence, e.g., HvNCED, HvS40, HvDhn1. Even though HvFP1 is induced during drought, senescence and the ABA treatment, its overexpression suppresses the ABA regulated genes. This indicates that HvFP1 is acting in a negative feedback loop connected to the ABA signaling. The genome-wide transcriptomic analysis via RNA sequencing revealed that the gain-of-function of HvFP1 positively alters the expression of the genes related to leaf development, photomorphogenesis, photosynthesis and chlorophyll biosynthesis. Interestingly, many of those genes encode proteins with zinc binding domains, implying that HvFP1 may act as zinc supplier via its HMA domain. The results show that HvFP1 is involved in a crosstalk between stress responses and growth control pathways.

Transcriptional Profiling of BpWRKY49 Reveals Its Role as a Master Regulator in Stress Signaling Pathways in Birch (Betula platyphylla)

“…The third gene we tested was BpHIP47, which is related to the heavy-metal-associated isoprenylated plant protein (HIPP) family. HIP proteins not only regulate heavy metals like Cu and Cd stress [73,74] but are also involved in other stresses including drought and salt stress [75,76]. Thus, BpWRKY49 may regulate salt stress in birch either directly by inducing salt-stress-related genes or indirectly by regulating ubiquitination of those genes which are involved in salt stress.…”

WHIRLY1 Acts Upstream of ABA-Related Reprogramming of Drought-Induced Gene Expression in Barley and Affects Stress-Related Histone Modifications

“…On the other hand, under these conditions, bidirectionally functioning WHIRLY1 specifically up-regulates the genes involved in chloroplast development and function. This bidirectional function is typical for regulatory proteins balancing such trade-offs between abiotic and biotic stress responses and, in addition, developmental processes [ 48 , 49 ]. This sensitive and flexible balancing of different central pathways is obviously specific to particular stress and developmental situations, allowing for efficient acclimation to an ever-changing environment.…”

Heavy Metal-Associated Isoprenylated Plant Proteins (HIPPs) at Plasmodesmata: Exploring the Link between Localization and Function

“…As previously mentioned, HIPP26 upregulates drought responses in Arabidopsis and N. benthamiana [ 45 , 46 ]. Various other HIPP s are upregulated in response to drought, cold, or hypoxia [ 2 , 37 , 38 , 48 , 49 , 85 ], or downregulated in response to heat stress [ 50 ] although direct evidence of a role in stress responses is still lacking in most cases. HIPP6 (in PD proteomes, Table 1 ) is upregulated by wound responses [ 53 ].…”