Advances in functional regulation mechanisms of plant aquaporins: Their diversity, gene expression, localization, structure and roles in plant soil-water relations (Review)

Abstract

Aquaporins are important molecules that control the moisture level of cells and water flow in plants. Plant aquaporins are present in various tissues, and play roles in water transport, cell differentiation and cell enlargement involved in plant growth and water relations. The insights into aquaporins' diversity, structure, expression, post-translational modification, permeability properties, subcellular location, etc., from considerable studies, can lead to an understanding of basic features of the water transport mechanism and increased illumination into plant water relations. Recent important advances in determining the structure and activity of different aquaporins give further details on the mechanism of functional regulation. Therefore, the current paper mainly focuses on aquaporin structure-function relationships, in order to understand the function and regulation of aquaporins at the cellular level and in the whole plant subjected to various environmental conditions. As a result, the straightforward view is that most aquaporins in plants are to regulate water flow mainly at cellular scale, which is the most widespread general interpretation of the physiological and functional assays in plants.

The responding relationship between plants and environment is the essential principle for agricultural sustainable development on the globe

“…From the angle of individual plant development, the plant-growth grand periodicity curve can also reflect and show the above-mentioned trend [4,5,23,32]. Besides, crop responses to soil water deficits (including nutrients) take a 'slow-fast-slow' shaped curve in terms of main physio-biochemical indices change, and this is in agreement with the plant-growth grand periodicity, which also illustrates this fact and the wide plasticity for plants [9,23,33,34,53]. Surely, concerted expression of corresponding genes in the crop gene regulatory network system makes it possible that we can see the phenotype and the phenotype change under given temporalspatial conditions 33,34,40,53].…”

“…Water deficits in soil environment also influence solute transport (ion and nutrient uptake of plants) to larger extent, which effects on photosynthetic reactions in plant chloroplasts in many ways [27][28][29]. This is the reason why ion homeostasis and redox state have been brought to attention [26][27][28][51][52][53]. The series of the above reactions and processes occurring at different biointerfaces is regulated and controlled spatially and temporally by a crop gene regulatory network system based on the response to crop developmental cues, through which plants can elegantly respond to changes of their environment [27,28,53].…”

“…Recent progress in molecular biology and bioinformatics (especially, DNA microarray technology), genomics, proteomics, and metabolomics has offered an insight into the crop gene regulatory network system, which is mainly composed of inducible genes (environmental factors and developmental cues), their expression programming, and regulatory elements (ciselement and trans-element), corresponding biochemical pathways, and diverse signal factors [53]. Under the condition of soil water deficits, related stress factors always result in overlapping responses, including anatomical, physiological, biochemical, molecular biological changes, which make the crop gene regulatory network system more complicated and difficult to explore.…”

“…This is the reason why ion homeostasis and redox state have been brought to attention [26][27][28][51][52][53]. The series of the above reactions and processes occurring at different biointerfaces is regulated and controlled spatially and temporally by a crop gene regulatory network system based on the response to crop developmental cues, through which plants can elegantly respond to changes of their environment [27,28,53]. This network system has been formed by the interaction between plants and environment for a long time in the process of evolution, and it will continue to evolve with environmental succession [12,14,27,28].…”

“…The elucidation of it will extremely and purposefully promote the sustainable utilization of plant resources and make the best use of its current potential at different scales [27,28,[34][35][36][37][38][39][40][41][42][43]. This molecular mechanism at least includes environmental signal recognition (input), signal transduction (many cascade biochemical reactions are involved in this process), signal output, signal responses and phenotype realization, which is a multi-dimension network system and contains many levels of gene expression and regulation [43][44][45][46][47][48][49][50][51][52][53]. On the basis of our recent work [42][43][44][45][46][47][48][49] and related publications from other laboratories over the world, we will focus on some important aspects involved in the mutual-responding relationship between plants and environment under abiotic stresses (e.g., drought, salinity, and high temperatures), and draw a possible blueprint for this frontier field between crop biology and plant biology.…”