You need to know much about Salt Over expression SOV genes, Homeostasis K, Na and Ca, Salt releasing apparatus and varieties sequestering Na Capabilities  

Ithink blue/mauve flower avail, they used blue gene from delphinium to create.

Trangenic blue roses have been reported by Katsumoto et al., 2007. Transgenic blue carnation has also been reported (Fukui et al., 2003), and I believe it is commercially available. Seems like a big thing in Japan.

The transgenic bule roses are available in market, but with less commercial value yet

Please see this story:

"The World's First Biotechnology-driven "Blue Roses" - synonym for the impossible - have been successfully developed."

http://www.suntory.com/news/2004/8826.html

This is a good report from "Plant Science Post":

Title: Violets are Blue and Roses Can Be Too (2016, Sept)

https://croplife.org/news/violets-are-blue-and-roses-can-be-too/

Below is one part of the article.

"First, scientists had to stop the production of red and orange pigments in roses by dialing down the relevant gene with RNA interference (RNAi). Then they inserted a delphinidin gene from a blue pansy and another gene from an iris that produces delphinidin. It took these three genes and 20 years of work to develop the blue rose!

The work is paying off as this flower is highly desirable in geographies like Asia where some Chinese fairytales portray blue roses as a symbol of love fulfilled. The biotech roses have been sold in Japan since 2009 and in North America since 2011."

I think that the use of today's CRISPR/Cas9 technology can even totally block the gene (compared to use RNAi).

thank you for your answer .

An example of blue roses on Japan market. The attached sample from レインボーローズ・バラ専門 花雅 cost: $ 36.67 (¥ 4,158).

http://global.rakuten.com/en/store/hanamasa-k/item/bq-rose-008h/?s-id=borderless_recommend_item_en