Relationship Between Phytohormones and Male Sterility in Thermo-Photo-Sensitive Genic Male Sterile (TGMS) Wheat

Abstract

Fertility alternation normally occurs in a novel type of thermo-photo-sensitive genic male sterile (TGMS) wheat whose recessive genes in the nucleus are expressed as virtually complete sterility under lower temperature and shorter daylight conditions, but as normal fertility under higher temperature and longer daylight conditions during the developmental period from meiosis of pollen mother cells (PMCs) to the early mononucleate stage of microsporogenesis. In order to provide more information about the mechanism(s) of fertility alternation in TGMS wheat, the relationship between fertility alternation and levels of phytohormones was analyzed by endogenous hormone quantification and exogenous hormone treatments in the present research. Sown at an earlier date with a relatively low temperature and short daylight, TGMS wheat was male sterile phenotypically. Pollen abortion mainly occurred at the mononucleate to bi-nucleate stages of microsporogenesis and pollen abortion was mainly of the spherical type. Levels of endogenous indole-3-acetic acid (IAA), abscisic acid (ABA) and gibberellic acid (GA 3 ) in the anthers were at lower levels, and zeatin riboside (ZR) was higher. Sown at a later date, when the temperature during the critical period for fertility alternation was relatively high and the daylight was long, TGMS wheat was almost as fertile as the normal genotype and the contents of endogenous IAA, ABA and GA 3 in anthers were at higher levels, and the content of ZR was at a lower level. At the critical period for fertility alternation, treatments with exogenous IAA, ABA, GA 3 or aminoethoxy vinylglycine (AVG), an inhibitor of ethylene biosynthesis, decreased the frequency of sterile pollen grains and increased the frequency of self-pollinated fertile florets. Treatment with exogenous 2-chloroethyl phosphonic acid (CEPA), a releaser of ethylene, increased the frequency of sterile pollen grains and decreased the frequency of self-pollinated fertile florets. It was thus suggested that the fertility alternation of TGMS wheat was closely related to levels of phytohormones in the anthers, and changes of endogenous hormone levels were among the important factors responsible for the fertility alternation of TGMS wheat.

Wheat Myo-inositol phosphate synthase influences plant growth and stress responses via ethylene mediated signaling

“…When we investigated TaMIPS-B over-expressing rice transgenic at reproductive stage and we observed a reduced in seed setting rate with maximum reduction in L2 which had highest level of MI. During heat stress, rate of evolution of ethylene in heat sensitive variety is higher than tolerant one, which is correlated to higher male sterility and results in reduced grain yield 31,32 . Decrease in seed setting rate in over-expressing TaMIPS-B transgenic might be because of over-production of ethylene which results in reduced fertility.…”

Expression of IPT in Asakura-sanshoo (Zanthoxylum piperitum (L.) DC. f. inerme Makino) Alters Tree Architecture, Delays Leaf Senescence, and Changes Leaf Essential Oil Composition

“…Leaf tissue of Asakura-sanshoo (0.2 g) was frozen in liquid nitrogen and then ground to a fine powder. Indole acetic acid (IAA), trans -zeatin ( trans- Z), and trans -zeatin riboside ( trans- ZR) were extracted and quantified using the methods described by Zhang et al ( 2006 ) and Wang and Xiao ( 2009 ), with some modifications. The extracts in the vials were injected into an HPLC equipped with a YWG-C 18 stainless-steel column (4.6 mm × 250 mm, 5 μm; Waters, Milford, MA, USA), coupled to an ultraviolet detector (G1314A; Agilent, Palo Alto, CA, USA).…”

Profiling of indole metabolic pathway in thermo-sensitive Bainong male sterile line in wheat (Triticum aestivum L.)

“…The main network disappeared, and only 2 sub-networks of indole metabolism and coenzyme A biosynthesis metabolism were kept 2000; Pan et al 2014). IAA content in anthers of sterile line was about 80% of fertile line in wheat male sterile line C49S and BNS (Zhang et al 2006(Zhang et al , 2013b(Zhang et al , 2016. Based on the transcriptional profiles, we found that IAA metabolism was a typical differential metabolic pathway in network between anthers and young panicles tissues.…”

“…A series of two-line system male sterile lines were found and applied in recent 20 years in China (Li et al 2006(Li et al , 2009(Li et al , 2011aZhang et al 2006;Zhao 2010). BNS is a thermo-sensitive genic male sterile line with good sterility and good self-conversion.…”